Obstetrics Flashcards
First trimester ?
Week 1 - 12
Second trimester?
Week 13 - 26
Third trimester ?
Week 27 - 42
Supine Hypotensive syndrome?
When the pregnant patient is placed in SUPINE, resulting in reduction of blood return to the heart resulting of the gravid uterus compressing the maternal IVC
Patients suffer from ; tachycardia, sweating, nausea, and pallor
These symptoms are alleviated when you assist the patient into DECUBITUS
TPAL?
Term
Premature
Abortions
Live births
(Should include the inquiry of previous pregnancies or fetal complications, diabetes, hypertension, infertility and the general health of other children at time of birth and currently)
Causes of first trimester bleeding ?
Ectopic pregnancy
Gestational Trophoblastic disease
Miscarriage
Blighted ovum
Embryonic demise
SubChorionic hemorrhage
Second trimester painful bleeding indicative of ?
Placenta ABRUPTION
Second trimester painless bleeding is indicative of ?
placenta PREVIA
Triple screen ?
Done between the weeks of 15 to 20
MSAFP, hCG, and estriol
Quadruple screen ?
Estriol/ hCG/ MSAFP
Additionally Inhibin - A
When are levels and NT measurement obtained ?
Weeks between 11 to 14
Levels ; hCG, estriol, and PAPP-A (pregnancy- associated plasma protein A)
And measuring the posterior fetal neck fold aka NT
Materni2Plus test?
Simple blood test that can be done early as 9 weeks ;
Reveal gender and highly accurate in detecting chromosomal anomalies such as ; trisomy 18, 21, and 13
DECREASED hCG levels indicative of ?
Abortion (misscarriage)
Anembryonic pregnancy
Ectopic pregnancy
Edwards Syndrome (18)
Turner syndrome /monosomy X (With hydrops)
Increased MSAFP levels indicative of?
Anencephaly
Cephalocele
Gastroschisis
Omphalocele
Patau / trisomy 13
Spina Bifida (meningocele or myelomeningocele)
Decreased MSFP indicative of ?
Downs Syndrome / trisomy 21
Edwards / trisomy 18
Turner Syndrome / Monosomy X
Decreased Estriol level indicative of ?
Down syndrome / trisomy 21
Edward syndrome / trisomy 18
Turner Syndrome/ monosomy x
First trimester measurements ?
Yolk sac
Gestational sac / MSD
CRL / Crown Rump Length
NT / translucency
Associated with pregnancy ?
Appendicitis (lower right quadrant pain)
Gallstones (right upper quadrant pain)
Hydronephrosis - with later term pregnancies (obstructing asymptomatic ureter)
(Back pain)
Abdominal circumference criteria?
TRANSVERSE
Fetal abdomen at the level of the umbilical vein and stomach
Also acceptable to be seen ;
Transverse thoracic spine, right adrenal gland, and gallbladder
Head circumference criteria ?
Measured from the outer perimeter of the skull at the level of the third ventricle, thalami and cavum septum pellucidum and falx cerebri
Head circumference criteria ?
Measured from the outer perimeter of the skull at the level of the third ventricle, thalami and cavum septum pellucidum and falx cerebri
(Taken at the same level as BPD)
From the outer to outer diameter
Typically more accurate since it’s independent from fetal head shape — providing a more consistent parameter for estimating gestational age
Femoral length criteria?
Sound beam is placed perpendicular to the long axis of the femoral shaft
Biparietal Diameter ?
Measure from the outer edge of the proximal skull to the inner edge of the distal skull (leading edge to leading edge)
Level of the thalamus, third ventricle, cavum septum pellucidum, and falx cerebri
Can be obtained from end of first trimester (week 13/14) in the axial plane
The cranial bones must be symmetric on both sides of the head
Biophysical point criteria ?
Thoracic movements (atleast one episode of stimulated fetal breathing lasting atleast 30 sec.)
Fetal movements (atleast three or more gross fetal body)
Fetal tone (atleast one flexion to extension of a limb or one hand opening/ closing)
Amniotic fluid (atleast one pocket of fluid measuring > 1 CM in vertical diameter in two perpendicular planes)
Nonstress Test (atleast two fetal heart accelerations)
(Each worth 2 points )
Fetal lie?
Either longitudinal or transverse
Fetal presentation?
Fetal body part closest to the internal os of the cervix
Cephalic is most common but baby can also present breech ;
Breech types?
Complete
Incomplete/ footling
Frank
Complete breech?
Fetal legs are flexed at the hips and there is flexion of the knees
Frank breech?
Fetal buttocks are closest to the cervix
Footling/ incomplete breech?
When there is extension of atleast one of the legs toward the cervix
The above image is of the gravid uterus of a 39-year-old patient who presented to the ultrasound department with a history of elevated MSAFP.
She states that the fetus appears to have been moving regularly, and she has had no pain or vaginal bleeding. What is the most likely diagnosis?
A.Spina bifida
B. Trisomy 18
C. Endometriosis
D. Anencephaly
Anencephaly
In the TPAL designation, the “L” refers to:
a. Living children
b. Lethal anomalies
c. Live births
d. Lost pregnancies
Live Births
All of the following are observed during a biophysical profile except:
a. Fetal tone
b. Thoracic movement
c. Fetal breathing
d. Fetal circulation
Fetal circulation
Which of the following would not be decreased in the presence of
Edwards syndrome?
a. Estriol
b. hCG
c. alpha-Fetoprotein
d. All would be decreased
All would be decreased
All of the following are produced by the placenta except:
a. alpha-Fetoprotein
b. hCG
c. PAPP-A
d. Inhibin A
AFP/ alpha fetoprotein (produced by the yolk sac and liver)
A myelomeningocele is associated with:
a. Down syndrome
b. Spina bifida
c. Edwards syndrome
d. Patau syndrome
Spina Bifida
The anechoic space along the posterior aspect of the fetal neck is the:
a. Nuchal fold
b. Nuchal cord
c. Nuchal translucency
d. Rhombencephalon
Nuchal Translucency
The premature separation of the placenta from the uterine wall before the birth of the fetus describes:
Placental ABRUPTION
Biophysical profile scoring is conducted:
a. Until the fetus cooperates
b. For 10 minutes
c. For 45 minutes
d. For 30 minutes
For 30 minutes
What is the fetal presentation when the fetal buttocks are closest to the cervix?
Frank breech
Which of the following would not typically produce an elevation in hCG?
a. Down syndrome
b. Anembryonic pregnancy
c. Triploidy
d. Molar pregnancy
Anembryonic pregnancy
The protein that is produced by the yolk sac, fetal gastrointestinal tract, and the fetal liver is:
AFP
Which of the following would be least likely associated with an elevation in MSAFP?
a. Anencephaly
b. Turner syndrome
c. Spina bifida
d. Myelomeningocele
Turners Syndrome
Trisomy 21 ?
Down’s syndrome
Trisomy 18 ?
Edwards syndrome
Trisomy 13?
Patau syndrome
Evolution of conceptus / zygote / blastocyst?
Mature ovum is released through ovulation / day 14, because the Graafian follicle ruptures and liberates the ovum into the distal portion of the tube (infundibulum)
The sperm and egg unite in the distal one - third of the fallopian tube (ampulla)
Conception usually occurs within the first 24 hours
The zygote formed transforms into the morula, which turns into the blastocyst which begins to implant into the decidualized endometrium at the uterine fundus
Blastocyst (inner/outer layer)?
Outer ;
Trophoblastic cells that produce hCG and eventually develops into the placenta and chorion (gestational sac)
Inner; develops into the embryo, amnion, umbilical cord, and the primary / secondary yolk sacs
Chorionic villi ?
Fingerlike projections of gestational tissue that attach to the decidualized endometrium
(allows transfer of nutrients from the mother to the fetus)
What occur during the 4th week of gestation?
The embryo is located between the yolk sac and the amnion
Primary yolk sac regresses
Chorionic and Amniotic membranes are formed
Outer ; chorionic sac
Inner ; amniotic sac
By the END of the 4th week ;
The secondary yolk sac becomes lodged between the chorion and amniotic membranes
Extraembryonic Coelom?
Aka chorionic cavity
Where the secondary yolk sac is located at the end of the fourth week of gestation
(Between the chorionic and amniotic membranes)
What occurs during the 4th week of embryo development ?
Alimentary Canal begins to form (foregut/ midgut/hindgut)
Neural tube begin to develop (fetal head and spine)
What occurs at 6 weeks of embryo development ?
All internal and external structures begin to develop
The obstacle of an inaccurate LMP being provided by the patient can be overcome by the following?
Referencing hCG levels in maternal circulation
Gestational sac AKA?
Chorionic sac
Lab test used to detect pregnancy ?
hCG
(Produced throughout pregnancy by the placenta)
Detected in maternal circulation early as 23 (days) menstrual/ gestational age
Earliest definitive sign of IUP ?
A gestational sac should be seen with transvaginal sonography with hCG levels between 1000 - 2000 mIU per mL
Average growth rate of the gestational sac?
1 mm per week
Ex. 5 weeks — > 5 mm gestational sac diameter / MSD
Normal hCG levels associated with normal IUP?
Doubles every 48 hours until it plateaus at the end of the first trimester and slowly decreases with advancing gestational age
Decreased levels of hCG compared to normal IUP indicates?
Ectopic pregnancy
Abortion/ miscarriage
Elevated levels of hCG compared to normal IUP indicates ?
Twin pregnancy
Complete Molar Pregnancy (significantly high levels of hCG)
First definitive sonographic finding of IUP?
Indentification of the gestational sac within the decidualized endometrium (thickened and echogenic)
Early gestational sac sonographic findings ?
First seen transabdominal by 5 weeks
Appearing as a small anechoic sphere within the decidualized endometrium
Growth rate ; 1mm/per day in early pregnancy
Intradecidual sign?
Small gestational sac in the uterine cavity surrounded by the thickened, echogenic endometrium
Double sac sign ?
Distinct appearance of the two layers of the DECIDUA separated by the anechoic fluid filled uterine cavity
Decidua CAPSULARIS/ PARIETALIS
Safe to assume that a round/ oval shaped fluid collection within the endometrium of a patient with a (+) pregnancy test and hCG levels above the discriminatory zone indicates?
Gestational sac
Chorionic Cavity ?
Space between the gestational sac and the amniotic sac
Location of the secondary yolk sac
Chorion Frondosum?
Decidualized tissue at the implantation site containing the chorionic villi
Fetal contribution of placenta
Fetal contribution of placenta ?
Chorionic frondosum
Chorion Laeve?
Portion of the chorion that does not contain chorionic villi
Decidua BASALIS?
Endometrial tissue at the implantation site
Maternal contribution of placenta
Maternal contribution of placenta ?
Decidua basalis
what is the earliest sonographic measurement obtained to date the pregnancy ?
MSD / mean sac diameter
(Relatively accurate form of dating but can only be used until a fetal pole is recognizable (sonographically)
MSD obtained by ?
Dimension L x W x H (divided by 3)
(By adding 30 to MSD (in milimeters) sonographer can estimate the gestational age in days)
Signs of potential pregnancy failure ?
Irregular shaped gestational sac
MSD > 25 mm that does not contain a fetal pole
First structure seen within the gestational sac ?
Secondary yolk sac
(Round, anechoic circular structure surrounded by a thin echogenic rim)
Located within the chorionic cavity (between the chorion and amnion)
Yolk sac is connected to the embryo via?
Vitelline duct / omphalomesenteric duct
Gestational sac consists of ?
Chorionic cavity
Amniotic cavity
Chorionic cavity ?
Between the amnion and the chorion
Fluid and the yolk sac is located
Amniotic cavity contents ?
Embryo and amniotic fluid
Amniotic membrane / amnion appearance ?
can be seen within the gestational sac as a thin, echogenic line loosely surrounding the embryo
When do the chorion and amnion typically fuse ?
Around the middle of the first trimester, by the 16th gestational week
Sonographic findings of embryo at 5 / 6 weeks ?
By 6 weeks with TV the embryo can be seen within the amniotic cavity adjacent to the yolk sac
Fetal heart motion is assessed with motion mode (M- mode) (between 5 to 6 weeks)
When the embryo is 4 mm , with definitive evidence by 5 mm
Growth rate; 1 mm/ per day
Often the first sonographic sign of a eminent embryologic demise ?
< 90 bpm
Bradycardia
Associated with a poor prognosis
Heart rate between 5 to 6 weeks ?
100 to 110 bpm
By 9 weeks heart rate should increase to?
150 bpm
From the second trimester to term heart rate ?
Around 150 bpm
Most accurate sonographic measurement of pregnancy ?
CRL / crown rump length
(From when the fetal pole is identified, till the second trimester and biometric measurements can be obtained )
Sonographic findings of embryo (7 to 8 weeks)?
Fetal limbs buds can be identified
Fetal head is larger than the body (bobble head)
Rhombencephalon may be seen within the fetal head as a round cystic structure
Stomach may also be seen in the upper abdomen at 8 weeks
Physical bowel herniation begins at 8 weeks — returns to the abdomen by 12 weeks
Physiological bowel herniation / migration occurs ?
Week 8 to 12
(If the midgut doesn’t not return into the abdomen by 12 weeks, follow up examination is warranted)
Fetus sonographic findings at the end of the first trimester ?
Fetal head ; within the lateral ventricles —> choroid plexus and seen separating the cerebral hemispheres ; falx cerebri
Fetal limbs more readily identified
Fetal movement
Fetal stomach
Urinary bladder
Umbilical cord
Spine
Developing placenta may be noted
With TV sonography the kidneys can be seen early as ?
13 to 14 weeks
Fetal abnormalities that can be detected at the end of the first trimester with TV - high resolution ?
Neural tube defects
Abdominal wall defects
Cardiac defects
Facial features (cleft palate)
Nasal bone
Disorders of the extremities
Placenta sonographic findings ?
May be seen developing by the end of the first trimester
Appears as a well defined, crescent shaped homogeneous mass of tissue along the margins of the gestational sac
Umbilical cord sonographic findings ?
Seen during the end of the first trimester as a tortuous structure connecting the fetus to the developing placenta
NT?
Vital part of early first trimester screening
Thin membrane along the posterior aspect of the fetal neck
Most common abnormalities associated with increased NT?
Trisomy 21
Trisomy 18
Turner’s syndrome
Congestive heart failure
Obtaining NT criteria ?
The margins of the NT edges must be clear enough for proper placement of the calipers.
2. The fetus must be in the midsagittal plane.
3. The image must be magnified so that it is filled by the fetal head, neck, and upper thorax.
4. The fetal neck must be in a neutral position, not flexed and not hyperextended.
5. The amnion must be seen as separate from the NT line.
6. The (+) calipers on the ultrasound must be used to perform the NT measurement.
7. Electronic calipers must be placed on the inner borders of the nuchal space with none of the horizontal crossbar itself protruding into the space.
8. The calipers must be placed perpendicular to the long axis of the fetus.
9. The measurement must be obtained at the widest space of the NT.
NT obtaining timeframe ?
Optimally measured between 11 to 13 weeks / 6 days
CRL measuring between ; 45 to 84 mm
NT dimmension should not exceed from week 11 to 13 and 6 days gestation?
< 3 mm
Associated early sonographic sign of Down syndrome ?
Increased NT
Absent/ hypoplastic nasal bone
Equal sign?
Appearance of a normal fetal bone and overlying nasal skin
Corpus Luteum Cyst associated with pregnancy ?
Most common functional cyst associated with pregnancy
Will usually enlarge due to high level of hCG exposure from the pregnancy and reach sizes up to 2 to 3 cm but can reach sizes up to 10 cm
Appears as a simple cyst, complex cyst with hemorrhagic components, as a hypoechoic mass or have a thick echogenic rim that displays increased colour doppler signal with low resistance spectral doppler waveform present
Could be confused for an ectopic pregnancy
Most common causes of pelvic pain with a positive pregnancy ?
Ectopic pregnancy
Ectopic pregnancy / EUP?
Pregnancy located anywhere other than the uterine or endometrial cavity (most commonly the fallopian tube)
Most common cause of pelvic pain with a positive pregnancy test
May lead to pregnancy loss, and in some cases even death
Ectopic pregnancy associations ?
ART
Fallopian tube scarring (essure device/ surgery)
PID ‘
Most common region for ectopic pregnancy?
Fallopian tube — ampulla segment
(Also can implant in the following areas :
isthmus of the tube, the fimbria, abdomen, interstitial portion of the fallopian tube (cornu of the uterus), ovary, and cervix,)
Increased risk of heterotopic pregnancy associated with ?
ART
Contributing factors to ectopic pregnancy ?
Previous ectopic pregnancy
Previous tubal surgery (including tubal sterilization)
History of pelvic inflammatory disease (salpingitis)
Undergoing infertility treatment / ART
Previous or present use of an intrauterine contraceptive device / IUD
Multiparity
Advanced maternal age
Classical clinical triad of Ectopic pregnancy ?
Pain
Vaginal bleeding
Palpable abdominal / pelvic mass
Also may present with ;
Amenorrhea
Low hCG compared to normal IUP levels
Shoulder pain ( secondary to intraperitoneal hemorrhage with diaphragmatic irritation)
Low hematocrit (with rupture)
Cervical motion tenderness
Sonographic findings of ectopic pregnancy ?
Extrauterine gestational sac with fetus and yolk sac seen
Adnexal ring sign, complete adnexal mass located between the uterus and ovary
Also a large amount of fluid located in the
Pelvis/POD / posterior cul de sac and Morrison pouch
Pseudogestational sac and a poorly decidualized endometrium
Most severe case of ectopic pregnancy ?
Interstitial
Due to the high vascular content
Prone to excessive hemorrhage
Potentially life threatening because the pregnancy may progress normally until spontaneous rupture occurs
Gestational sac that is located in the superolateral portion of the uterus
( Assess for thinning of the myometrium surrounding the gestation that is located within the interstitial portion of the fallopian tube )
Treatment of ectopic pregnancy ?
Methotrexate
Administered either by ;
Injected into the EUP (sonographic guidance) or taken intramuscularly
When they are confined to the fallopian tube and size less than < 4 /5 cm
Gestational Trophoblastic Disease ?
Complete molar pregnancy or
partial incomplete molar pregnancy
Group of disorders that result from abnormal combination of male/ female gametes
GTD results in excessive growth of the trophoblastic cells, which produces hCG — which results in markedly high hCG levels and theca lutein cysts likely developing
(Typically benign but does have a malignant potential)
Most common type of gestation trophoblastic disease?
Complete / molar pregnancy
Sonographic findings of gestational trophoblastic disease (complete molar pregnancy) ?
Complex mass within the uterus
Color doppler may reveal hypervascularity around the mass but not within it
Vesicular snowstorm appearance secondary to placenta enlargement
Multiple, variable - sized cysts replacing the placenta tissue (hydropic chorionic villi)
Bilateral ovarian theca lutein cysts (large and multiloculated masses)
Sonographic findings of partial molar pregnancy ?
Complex mass within the uterus partially filling the uterine cavity adjacent to the gestational sac
Vesicular snowstorm appearance secondary to placenta enlargement
Multiple variable sized cysts replacing the placenta tissue (hydropic chorionic villi)
Triploid fetus
Symptoms of gestational trophoblastic disease?
Hyperemesis gravidarum
Markedly high hcg level (> 100 000 mIU per mL) leading to bilateral theca lutein cysts developing
Heavy vaginal bleeding with possible passageway of grapelike molar clusters
Hypertension
Uterine enlargement
Even hyperthyroidism and possibly preeclampsia or eclampsia
Diagnosis of blighted ovum / anembryonic gestation ?
No evidence of a fetal pole or yolk sac within the gestational sac
Often the gestational sac is irregular shaped with a poor decidual reaction
Patients often have lower hCG levels, vaginal bleeding and reduction in pregnancy symptoms
Embryonic demise / poor outcome associated with the following ?
Heart rate less < 90 bpm (bradycardia)
Not seeing heart activity within a 5mm fetal pole with endovaginal sonography
Yolk sac that is echogenic, enlarged, distorted, and/ or calcified
cause of embryonic demise?
May be idiopathic or linked with chromosomal abnormalities
Sonographic finding of impending fetal demise ?
Present small for dates and typically have vaginal bleeding with a closed cervix.
Gestational sac small compared to the CRL length
Yolk sac diameter ?
< 7 mm
Termination of a pregnancy before viability is termed ?
Miscarriage or Abortion
Abortion categories ?
Threatened
Complete
Incomplete
Missed
Inevitable
Septic
Elective
Abortion / miscarriage symptoms ?
Vaginal bleeding
Pelvic cramping
Passage of products of conception
Low hCG levels compared to IUP
First trimester miscarriages have been linked with ?
Idiopathic or
Ovarian abnormalities
Aneuploid fetus
Maternal infections
Physical abuse
Trauma
Drug abuse
Maternal endocrine abnormalities
Anatomic factors
Threatened abortion ?
Vaginal bleeding before 20 weeks
Closed cervical os
Low fetal heart rate
Complete / spontaneous abortion ?
All products of conception expelled
No intrauterine products of conception identified
Prominent endometrium (may contain hemorrhage)
Incomplete abortion ?
Parts of product of conception expelled
Thickened and irregular endometrium
Enlarged uterus
Missed abortion ?
Fetal demise with retained fetus
No detectable feta rate motion detected
Abnormal fetal shape
Inevitable abortion?
Vaginal bleeding with dilated cervix
Low lying gestational sac
Open internal os of cervix
SubChorionic hemorrhage ?
Essentially a bleed between the endometrium and gestational sac
Result from implantation of fertilized ovum into the uterus with subsequent low pressure bleeding / spotting and possible cramping
SubChorionic hemorrhage sonographic findings ?
Crescent anechoic/ hypoechoic/ echogenic shaped area adjacent to the gestational sac (echogenicity depends on age of hemorrhage)
May resemble a second gestational sac
Large subchorionic bleeds have been associated with ?
Miscarriage and stillbirth
Acute SubChorionic hemorrhage appearance ?
Recent bleeds are hyperechoic or isoechoic to the placenta
Chronic subchorionic hemorrhage appearance?
(Long standing)
Anechoic or hypoechoic
Sonographic findings of fibroids associated with pregnancy ?
Common benign pelvic mass that can often be identified during the first trimester exam
Since they are stimulated by estrogen — they might increase in size with the ongoing pregnancy
Increased risk associated with early pregnancy failure, especially with multiple gestations
Cervical and lower segment types are most relevant since they might pose a dilemma at delivery
Needs to be differentiated from myometrial contractions
Myometrial contractions sonographic findings ?
Smooth muscle contraction
Appears like a myometrial fibroid but doesn’t consistently alter the shape of the uterine myometrium like a fibroid does
They typically resolve within 20 to 30 minutes
Symptoms of fibroids associated with pregnancy ?
Positive pregnancy test
Pelvic pressure
Menorrhagia
Palpable pelvic mass
Enlarged and bulky uterus (if multiple)
Urinary frequency
Dysuria
Constipation
IUD associated with pregnancy ?
Failed IUD / ineffective
Seen as an echogenic structure within the uterine cavity adjacent to the gestational sac
May produce shadowing
With a normal pregnancy, the first structure noted within the decidualized endometrium is the?
Chorionic Sac
Sonographically, a normal-appearing 7-week IUP is identified. Within the adnexa, an ovarian cystic structure with a thick, hyperechoic rim is also discovered. What does this ovarian mass most likely represent?
a. Theca lutein cyst
b. Corpus luteum cyst
c. Corpus albicans
d. Ectopic pregnancy
Corpus Luteum cyst
The first sonographically identifiable sign of pregnancy is the:
a. Amnion
b. Yolk sac
c. Decidual reaction
d. Chorionic cavity
Decidual Reaction
The first structure noted within the gestational sac is the:
a. Yolk sac
b. Embryo
c. Decidual reaction
d. Chorionic sac
Yolk Sac
What hormone maintains the corpus luteum during pregnancy?
a. Estrogen
b. Progesterone
c. Follicle-stimulating hormone
d. hCG
hCG / human chorionic gonadotropin
All of the following are clinical features of an ectopic pregnancy except:
a. Pain
b. Vaginal bleeding
c. Shoulder pain
d. Adnexal ring
Adnexal ring
In the early gestation, where is the secondary yolk sac located?
a. Chorionic cavity
b. Base of the umbilical cord
c. Embryonic cranium
d. Amniotic cavity
Chorionic Cavity
All of the following are sonographic findings consistent with ectopic pregnancy except:
a. Decidual thickening
b. Complex free fluid within the pelvis
c. Bilateral, multiloculated ovarian cysts
d. Complex adnexal mass separate from the ipsilateral ovary
Bilateral multiloculated ovarian cysts (theca lutein) so can’t be associated with EUP
Malignant forms of gestational trophoblastic disease ?
Choriocarcinoma and invasive mole
Which of the following is the most likely metastatic location for GTD?
a. Rectum
b. Pancreas
c. Spleen
d. Lungs
Lungs
(Liver and spleen as well)
All of the following are clinical findings consistent with a complete molar pregnancy except:
a. Vaginal bleeding
b. Hypertension
c. Uterine enlargement
d. Small for dates
Small for dates
All of the following may be sonographic findings in the presence of an ectopic pregnancy except:
a. Pseudogestational sac
b. Corpus luteum cyst
c. Adnexal ring
d. Low beta-hCG
Low beta hCG
Initially the brain is divided into three primary vesicles ?
Forebrain (prosencephalon)
Midbrain (mesencephalon)
Hindbrain
(rhombencephalon)
(May be seen within the fetal cranium during the end of the first trimester)
Eight cranial bones ?
Parietal (superior / lateral)
Temporal (inferior / lateral)
Frontal (anterior)
Occipital (posterior)
Sphenoid (lateral)
Ethmoid (anterior (between orbits)
Craniosynostosis ?
Premature fusion of the sutures
Leads to an irregular shaped head
Spaces that exist between the forming fetal bones ?
Fontanelles/ soft spots
Can be used as acoustic windows to assess for infantile intracranial hemorrhage or suspected brain anomalies
Bregma?
Anterior Fontanel when completely filled with bone
posterior skull suture filled with bone ?
Lambda
Foramen Magnum ?
Opening at the base of the cranium where the spinal cord travels through
Brain can be divided into?
Cerebrum
Cerebellum
Cerebrum ?
Right / Left hemispheres
Largest part of the brain
Contains multiple sulci and gyri
Cerebral lobes?
Frontal
(2) Temporal
(2) Parietal
Occipital
Cerebrum is divided into a right and left hemisphere by ?
Interhemispheric fissure
Appears as a echogenic linear formation coursing through the midline
Cerebral hemispheres are linked in the midline by the corpus callosum
Cerebral hemispheres are linked in the midline by the ?
Corpus callosum
Corpus callosum ?
Thick echogenic band of tissue within the midline that provides communication and connection between the right and left halves of the brain
Should be completely intact between 18 - 20 weeks
Meninges layers (O/I)?
Outermost; dura mater
Middle; arachnoid membrane
Innermost ; pia mater
Meninges ?
Three protective layers that cover the brain and spinal cord and comprised of three layers ;
Dura Mater (outer)
Arachnoid membrane
Pia Mater (inner)
Cavum Septum Pellucidum ?
Midline anterior portion of brain between the frontal horns and lateral ventricles
(Does NOT communicate with the lateral ventricles)
Appears as a anechoic box shaped structure in axial / trv plane
Typically seen between 18 to 37 weeks
Closure of this structure typically occurs before birth or shortly after
Absence of the Cavum Septum Pellucidum associated with ?
Multiples cerebral malformations, including ACC / Agenesis of the Corpus Callosum
Thalamus ?
Vital
Two lobes are located on both sides of the third ventricle
Can NOT be confused for the cerebral peduncles which are more inferiorly positioned in the brain
Mass intermedia ?
Aka Interthalmic adhesion
Passes through the third ventricle to connect the two lobes of the thalamus
Third ventricle passes through
Lateral ventricles location ?
Located on both sides of the falx cerebri within the cerebral hemispheres
AKA ; right/ left
Consists of ;
Frontal , Temporal, and Occipital horns
Ventricles of the brain function ?
Provide cushioning for the brain
Choroid Plexus?
Located within the atria of both lateral ventricles
Mass of cells responsible for the production of CSF
Each lateral ventricle communicates with the third ventricle via ?
Foramen of Monro
(Located between the two lobes of the thalamus)
Third ventricle ?
Contains mass intermedia / interthalamic adhesion
Each lateral ventricle communicates with the third ventricle
Only seen when enlarged or surrounded by CSF
What connects the third and fourth ventricle inferiorly ?
Aqueduct of Sylvius / cerebral aqueduct
(Long , tube - like structure)
Fourth ventricle ?
Located anterior to the cerebellum within the midline of the brain
Has 3 apertures for CSF to travel through
Lateral ; foramina of Luschka
Foramina of Luschka ?
Two lateral apertures of the fourth ventricle located within the midline, anterior to the cerebellum
Purpose is to allow CSF to travel from the fourth ventricle to the subarachnoid space around the brain
Which aperture of the Foramen of Luschka allows CSF to pass from the fourth ventricle to the cisterna magna and subarachnoid space ?
Foramen of Magendie
CSF pathway ?
Greater part of CSF is produced by the cells of the choroid plexus
(Located within the trigone of the lateral ventricles)
Moves from the lateral ventricles to the fourth ventricle via the foramen of Monro
From the third ventricle to fourth ventricle via aqueduct of sylvius
Once in the fourth ventricle, the fluid can exit either through the lateral or median aperture
(Foramen of Luschka / Lateral )
(Foramen of Magendie /median)
Responsible for reabsorption of CSF into the venous system ?
Arachnoid villi
(Occurs at the superior sagittal sinus) which is located along the superior surface of the cerebrum within its midline
Cisterna Magna ?
Located posterior fossa of the cranium
Appears as a posterior fluid filled space
Posterior to the cerebellum between the cerebellar vermis and interior surface of the occipital bone
Common finding to see small septations within the cisterna magna
Cerebellum?
Located in the posterior fossa in the cranium
Consists ; left / right side
Appears dumbbell shaped anterior to the cisterna magna
Distorted cerebellum shape is associated with?
Spina bidfia
Arnold Chiari Malformations
OFD ?
Occipital Frontal
diameter
Obtained at the same level as the HC and BPD
Caliper is placed from the middle of the anterior frontal bone in the middle of the occipital bone
Brachycephaly ?
Rounder /short / wide head shape
Cephalic index ; > 85
Dolichocephalic / Scaphocephaly ?
Enlongated and narrow head shape
Cephalic Index ; < 75
Cephalic Index formula ?
BPD / OFD x 100 = CI
(Used to indicate the shape of the fetal head)
Lateral ventricle measurement ?
In TRV and the level of the atrium
< 10 mm
Lateral ventricle measurement indicating that ventriculomegaly is present?
> 10 mm
Lemon shape fetal head associated with ?
Chiari II malformation
strawberry head shape associated with?
Trisomy 18 / Edwards syndrome
Cloverleaf shape skull is associated with?
Thanatophoric Dysplasia
Microcephaly is associated with?
TORCH infections
Trisomy 13/ Patau
Trisomy 18/ Edward
Meckel Gruber Syndrome
Fetal Alcohol syndrome
Macrocephaly is associated with?
Hydrocephalus
Hydranencephaly
Intracranial Tumor
Familial inheritance
Beckwith - Wiedemann syndrome
associated with brachycephaly ?
Craniosynostosis
Trisomy 21 / Down syndrome
Trisomy 18 / edward syndrome
Dolicocephaly is associated with?
Craniosynostosis
Transcerebellar measurement ?
Growth rate from 14 to 21 weeks —
1 mm / per week
Ex. 16 week fetus with 16 mm cerebellum
Measured in the transverse plane at the same level of the cisterna magna and thalamus
Depth of the cisterna magna ?
NOT measure more < 10 mm deep
Less < 2 mm in the transcerebellar plane
Consistent with mega cisterna magna and Dandy - Walker complex ?
Cistern magna deeper than > 10 mm
Measurement of transcerebellar ( < less than 2 mm ) is worrisome of ?
Arnold Chiari II malformation
Hydrocephalus ?
Refers to dilation of the ventricular system caused by an increased volume of CSF, resulting in increased intraventricular pressure
Caused by obstruction to the flow of CSF
May be caused by chromosomal aberration and intrauterine infections
Can either be classified as mild/ moderate/ or severe
Communicating or Noncommunicating types
Ventriculomegaly?
Abnormal enlargement of the ventricles
Most common cranial abnormality
> 10 mm atrial diameter measurement
Dangling cord sign
Most common cranial abnormality ?
Ventriculomegaly
Dangling Cord sign ?
VENTRICULOMEGALY
Describes the sonographic appearance of the choroid plexus “ hanging” and surrounded by CSF, within the dilated lateral ventricle
Noncommunicating Hydrocephalus ?
Obstruction level is located WITHIN the ventricular system
Communicating Hydrocephalus ?
Obstruction lies OUTSIDE the ventricular system
Aqueductal Stenosis ?
Most common cause of hydrocephalus in utero
Involves the aqueduct of Sylvius (located between the third and fourth ventricle) may be narrowed, hence preventing the flow of CSF
Causes the third ventricle and both the lateral ventricles to expand,
with the fourth ventricle remaining normal
Hydranencephaly ?
Fatal condition, most dying within a year of life
Entire cerebrum is replaced by a large sac containing CSF
Falx cerebri may be partially /completely absent, where as the brain stem and basal ganglia are maintained and surrounded by CSF
Thalamus may be seen, but there will be no cerebral cortex seen
Causes of hydranencephaly ?
Bilateral occlusion of the internal carotid arteries
Or
Intrauterine infections such as ;
Cytomegalovirus or toxoplasmosis
(Which BOTH lead to destruction of the cerebral hemispheres)
Hydranencephaly appearance ?
Seems to appear normal in the first trimester, and becomes more apparent by the second and third trimester
NO cerebral mantle is present
(Can be difficult to differentiate from severe ventriculomegaly and holoprosencephaly)
Holoprosencephaly ?
Alobar/ Semilobar/ Lobar
Midline brain anomaly that is associated with brain defects and atypical facial structures
50 - 70 % patients suffer as well from trisomy 13 / PATAU syndrome
Alobar Holoprosencephaly ?
Most SEVERE form, can be consistent with life
Cortex shape can either be ; pancake, ball, or cup
Alobar holoprosencephaly is diagnosed with what sonographic findings ?
Absence of the corpus callosum, CSP, third ventricle, Interhemispheric fissure, and falx cerebri
Horseshoe shaped monoventricle and the lobes of the thalamus are fused and more echogenic
The cerebellum and brain stem remain intact
Lobar Holoprosencephaly ?
Least severe form
Can be consistent with life, most patients suffer from severe mental retardation
There are varying degrees of fusion of midline structures
Cyclopia ?
Orbits are fused and contain a single eye, and proboscis, a false nose situated above the orbits
Associated with holoprosencephaly
Facial abnormalities associated with holoprosencephalon ?
CYCLOPIA
PROBOSCIS
Anopthalmia
Hypotelorism
Median cleft lip
Cebocephaly
Dandy Walker Malformation ?
Classification with larger group of disorders referred to as dandy walker complex — spectrum of posterior fossa abnormalities that involve cystic dilation of the cisterna magna and fourth ventricle
Thought to be caused by development abnormality in the roof of the fourth ventricle
Associated with hypoplastic or agenesis of the cerebellar vermis
Appearance of Dandy Walker Malformation?
Enlarged cisterna magna that communicates with a distended fourth ventricle through a defect in the cerebellum
Cerebellar vermis is either partially/ completely absent
Associated anomalies of dandy walker malformations ?
Agenesis of corpus callosum
Ventriculomegaly
Holoprosencephaly
Cephaloceles
Mega cisterna magna sonographic findings ?
Enlarged cisterna magna WITHOUT the involvement of the fourth ventricle
May be confused with DWM
Measuring more > 10 mm deep
Care must be taken to assess for an INTACT CEREBELLAR VERMIS
Corpus collosum is completely formed by?
Week 18
What develop at the same time as the corpus callosum ?
CSP
(Located inferior to the corpus callosum)
There is usually simultaneous agenesis of both brain structures (corpus callosum and CSP)
Non existence of corpus callosum and CSP has been linked to?
Anomalies such as Apert syndrome, Holoprosencephaly, DWM, aquedutal stenosis, trisomy 18, trisomy 8 and Trisomy 13
Sunburst manifestation?
Sulci is a straightforward and discernible for agenesis of CSP / corpus callosum
Spoke wheel pattern indicative of ?
Agenesis of corpus callosum
course of sulci (tend to be mor perpendicular or in a radial arrangement)
(Sagittal)
Colpocephaly?
Small frontal horns and enlarged occipital horns
Distinct teardrop shape of lateral ventricles
SONOGRAPHIC FINDINGS OF AGENESIS OF THE CORPUS CALLOSUM AND CAVUM SEPTUM PELLUCIDUM
- Partial or complete absence of the corpus callosum and absence of the CSP (after
18 weeks) - “Sunburst” sign–radial arrangement of the sulci which produces a “spoke wheel” pattern
- Colpocephaly - small frontal horns and enlarged occipital horns (teardrop-shaped lateral ventricles)
- Elevated and dilated third ventricle
Normal course of sulci within the fetal brain ?
Travel parallel to the corpus callosum
Schizencephaly ?
Associated with the development of fluid filled clefts within the cerebrum
Cause is unknown
Associated with intrauterine exposure to illicit drugs
OPEN / CLOSE lip types
Associated with corpus callosum and CSP, and ventriculomegaly
Porencephaly ?
Rare condition in which a cyst communicates with the ventricular system
Hemorrhage within one or both of the cerebral hemispheres — as the hemorrhage changes state it will form into a cystic cavity and eventually communicate with the lateral ventricle of the affected side
May be caused by ischemic events or vascular occlusion within the brain
May be confused for arachnoid cysts (but they do NOT communicate with the ventricular system)
Lissencephaly ?
Smooth brain
Condition where no sulci and gyri are present within the cerebral cortex / brain
Not typically diagnosed till the third trimester or postnatally also almost alway carries a poor prognosis
Choroid Plexus Cyst ?
Typically regress by the end of the third trimester.
Associated with trisomy 18 / Edwards syndrome
Measure more than > 2 mm, round and anechoic and have smooth walls
Neural tube defects occurs when ?
Embryonic neural tube fails to close
Neural tube defect types ?
Cephaloceles
Various spinal dysraphisms
Anencephaly
Spina Bifida
Most common type of neural tube defects ?
Anencephaly
Spina Bifida
Linked with neural tube defects ?
Maternal diabetes
Use of valproic acid (seizure medication)
Chromosomal anomalies ; edwards/ trisomy 18, patau/ trisomy 13, and triploidy
Neural tube defects diagnosed by ?
Combination of sonography, amniocentesis, and/ or triple maternal screening (hCG, estriol, and MSAFP)
MSAFP especially when there is an opening in the cranium or spine
Elevated levels of MSAFP have been associated with ;
Gastroschisis
Omphalocele
Multiple gestations
Fetal demise
Incorrect gestational dating
Absence of cranial vault above the bony orbits ?
Acrania
Anencephaly?
No cerebral hemispheres present
Elevated MSAFP
Absent cranial vault
Froglike facies / or bulging eyes
Fatal
Arnold Chiari II malformation ?
Group of cranial abnormalities associated with Spina Bifida
May result in a mass that protrudes from the spine
Depending on contents ; Meningocele or myelomeningocele
Most common involving distal lumbosacral region
Lemon sign and
banana sign
Spina Bifida sonographic findings ? (Arnold Chiari II malformation)
Scalloping of frontal bones ; lemon sign
Cerebellum becomes displaced inferior and posteriorly ; banana sign
(Cisterna magna is completely obliterated)
Lateral ventricles will be distorted in shape
Colpocephaly present ;
(Frontal horns small/ slit like and occipital horns will be enlarged)
Cephalocele?
Protrusion of intracranial contents
Dandy walker Malformation key points ?
Enlargement of cisterna magna > 10 mm (AP)
Absent cerebellar vermis
Enlarged fourth ventricle
Arnold Chiari II malformation key points ?
Spina Bifida
Obliterated cisterna magna
Banana shaped cerebellum
Lemon shaped skull (scalloping/ flattening of frontal bones)
Cephalocele?
Protrusions of intracranial contents through a defect in the skull
Most commonly seen in the OCCIPITAL region
Have varying
sonographic appearance
Encephaloceles contents?
Brain tissue
Encephaloceles ?
Common finding with Meckel Gruber syndrome
Meningocele ?
Meninges only
(Pia mater / arachnoid / dura mater)
Encephalomeningocystocele?
Contains meninges, brain tissue, and lateral ventricles
TORCH ?
Toxoplasmosis
Other agents
Rubella
Cytomegalovirus
Herpes simplex virus
Sonographic intracranial findings consistent with intrauterine infection ?
Calcifications around the ventricles and ventriculomegaly present
Most common intracranial tumor found in utero ?
Teratoma (hair/sebum,/fat)
Teratoma ?
Contains tissue such as ;
Hair , sebum, and fat
Most often appears as a complex masses that distort the normal architecture of the brain
Choroid plexus papillomas ?
Found within the choroid plexus and produce an increased production of CSF — leading to ventriculomegaly
Sonographic findings of brain tumors ?
Venticulomegaly
Macrocephaly
Intracranial calcifications
Corpus Callosum lipoma?
May be present with agenesis of corpus callosum
(Lipoma appear as solid echogenic mass)
Intracranial hemorrhage ?
Common worry for premature (weighing < 1500 g and born before 32 weeks)
Premature fetus?
< 1500 grams weight
Born before < 32 weeks
Most common risk factor for fetal intrauterine hemorrhage?
Maternal platelet disorders
Predisposing factors of intracranial hemorrhage ?
Maternal use of cocaine
Trauma
History of amniocentesis
Maternal platelet disorders
Germinal matrix ?
Group of thin walled, pressure - sensitive vessels located in the subependymal layer of the ventricles
Prone to rupture secondary to thin walls
Hemorrhage can spread into the lateral ventricle, often leading to noncommunicating hydrocephalus, because the clot obstructs the narrowed regions of the ventricular system
Normal cerebral circulation typically demonstrates ?
High impedance with continuous forward flow throughout the cardiac cycle
MCA can be assessed for fetal hypoxia in SGA fetus
brain - sparing effect ?
When fetal hypoxia occurs, redistribution of blood to the vital organs — such as the brain — occurs in order to spare it from damage
Middle Cerebral Artery doppler findings ?
Pulsatility index varies with gestational age, but normally decreases with pregnancy progressing toward term
Resistance pattern should be greater > umbilical artery
MCA/ umbilical artery (RI) Resistive index ?
Normally above > 1.0
(Considered abnormal under < 1.0)
Vein of Galen Aneurysm?
Arteriovenous malformation that occurs within the brain
Appears as a large, anechoic mass within the midline of the cranium that interrogated with colour/ power doppler reveals turbulent venous and arterial flow
Fetus will suffer from hydrops and cardio mealy
Newborns are prone to suffer ;
Increased cardiac output and congestive heart failure
With what structure does the posterior fossa cyst associated with DWM communicate?
a. Fourth ventricle
b. Third ventricle
C. Cerebellar vermis
d. Cerebral aqueduct
Fourth ventricle
Double fold of dura mater that divides the cerebral hemispheres ?
a. Cerebellum
b. CSP
c. Corpus callosum
d. Falx cerebri
Falx Cerebri
The “sunburst” of the cerebral sulci is a sonographic finding of:
a. DWM
b. Agenesis of the corpus callosum
c. Colpocephaly
d. Hydranencephaly
Agenesis of Corpus Callosum
Which of the following is a genetic disorder that includes craniosynostosis, midline facial hypoplasia, and syndactyly?
a. Lobar holoprosencephaly
b. Beckwith-Wiedemann syndrome
c. Arnold-Chiari II malformation
d. Apert syndrome
Apert syndrome
The third ventricle communicates with the fourth ventricle at the:
a. Foramen of Magendie
b. Foramen of Luschka
C. Foramen of Monro
d. Aqueduct of Sylvius
Aqueduct of Sylvius
The fourth ventricle is located:
a. Posterior to the CSP
b. Between the frontal horns of the lateral ventricles
c. Anterior to the cerebellar vermis
d. Medial to the third ventricle
Anterior to the cerebellar vermis
- The structure located between the two lobes of the cerebellum is the:
a. Cerebellar vermis
b. Cerebellar tonsils
c. Falx cerebri
d. Corpus callosum
Cerebellar Vermis
Normal shaped skull ?
Mesocephaly
What fetal suture is located within the frontal bone along the midline of the forehead?
a. Squamosal suture
b. Sagittal suture
c. Lambdoidal suture
d. Metopic suture
Metopic suture
What cerebral malformation is as a result of agenesis or hypoplasia of the cerebellar vermis?
a. Arnold-Chiari Il malformation
b. Schizencephaly
c. Mega cisterna magna
d. DWM
Dandy walker malformation / DWM
What cerebral malformation is as a result of agenesis or hypoplasia of the cerebellar vermis?
a. Arnold-Chiari Il malformation
b. Schizencephaly
c. Mega cisterna magna
d. DWM
Dandy Walker Malformation
Facial abnormalities associated with Holoprosencephaly?
Hypotelorism
Cebocephaly
Ethmocephaly
Cyclopia
And cleft lip with / without cleft palate
Results from the failure of the optic vessel to form ?
Microphthalmia or Anophthalmia
Associated with trisomy 13 / PATAU and trisomy 18/ EDWARDS
Most common cause of hypertelorism ?
Anterior placed cephalocele which displaces the orbits laterally
Also associated with craniosynostosis and many chromosomal abnormalities
Most common cause of hypotelorism ?
Holoprosencephaly with trisomy 13 commonly
Low set ears have been associated with ?
Trisomy 13/ 18 and 21
Microtia has been linked to ?
Down’s syndrome/ trisomy 21
Fetal lip typically closes when ?
Between 7 to 8 weeks
Fetal palate typcially closes ?
By 12 weeks
Abnormal or incomplete closure of the lip / palate ?
Results in cleft lip or palate or may exist together
Most common congenital abnormalities and have been associated with many syndromes and congenital anomalies ?
Cleft lip with coexisting cleft palate
Cleft lip / palate have been associated with ?
Holoprosencephaly
Trisomy 13 / Patau
ABS / amniotic band syndrome
Macroglossia has been associated with ?
Beckwith - Wiedemann syndrome
Down’s syndrome
Macroglossia can be hard to distinguish from Epiganthus because ?
They are both mostly solid structures appearing
But Epiganthus typically contains heterogenous tissue, whereas the enlarged tongue appears completely solid
Macroglossia ?
Continuous protrusion of the tongue
Associated with Down’s syndrome and beckwith wiedemann syndrome
Appears as a totally solid mass of tissue protruding the fetus mouth
Micrognathia has been linked to ?
Small mandible and recessed chin
Associated with trisomy 13 and trisomy 18
And several other chromosomal anomalies and syndromes
Seen best in sagittal view of the fetal face to diagnose
Cystic Hygroma ?
Results from abnormal accumulation of lymphatic fluid within the soft tissue
TURNERS syndrome
Most commonly seen in the neck
Cystic hygroma appearance ?
Cystic neck mass divided in the midline by a thick fibrous band of tissue
May contain smaller cystic areas with internal septations
Cystic Hygroma associated with ?
TURNERS syndrome
Fetal hydrops
Aneuploidy
Trisomy 21 / Downs
Trisomy 18 / Edwards
Trisomy 13 / Patau
Nuchal fold ?
< 6 mm
Can be obtained from 15 to 21 weeks
(Taken later than the nuchal translucency )
Fetal goiter ?
Can be the cause of over treatment of maternal Graves disease, iodine deficiency, or hypothyroidism
Appears as a fetal neck mass
Can cause compression of the trachea or esophagus / fetal swallowing may be inhibited— resulting in polyhydramnios
Other possible solid or complex appearing fetal neck masses such as ?
Lymphangioma
Hemangioma
Cervical teratoma
Branchial cleft cyst
Thyroglossal duct cyst
Oral teratoma ?
Epignathus
Which of the following would be most difficult to detect sonographically?
a. Cleft lip and cleft palate
b. Isolated cleft lip
c. Isolated cleft palate
d. Isolated median cleft
Isolated cleft palate
Close-set eyes and a nose with a single nostril is termed:
a. Cebocephaly
b. Cyclopia
c. Ethmocephaly
d. Epignathus
Cebocephaly
At what level is the nuchal fold measurement obtained?
a. Cavum septum pellucidum
b. Occipital horns of the lateral ventricle
C. Brain stem
d. Foramen magna
Cavum Septum Pellucidum
Fusion of the orbits is termed:
a. Microglossia
b. Cebocephaly
c. Cyclopia
d. Ethmocephaly
Cyclopia
The condition in which there is no nose and a proboscis separating two close-set orbits is:
a. Ethmocephaly
b. Epignathus
c. Micrognathia
d. Cebocephaly
Ethmocephaly
Nuchal Fold measurement timeframe ?
Between 15 to 21 weeks
Bones of the cranium and spine begin to form ?
6 to 8 weeks
(As pregnancy progresses the bones begin to ossify and become more echogenic, easier for the sonographer to see )
Spine segments ?
Cervical
Thoracic
Lumbar
Sacrum
Coccyx
Appearance of the fetal spine ?
Between the two laminar and posterior to the centrum, lies the vertebral column
( runs the entire length of the spine and contains the spinal cord )
Appears as a hypoechoic linear structure
Spina bifida ?
Associated with ARNOLD CHIARI II malformation
LUMBOSACRAL region
Pressure of a large mass in the distal spine pulling on the spinal cord causes malformations of the cranium and intracranial contents
LEMON shaped head
Banana shaped cerebellum (from being displaced inferiorly)
Lateral ventricle dilated
Frontal horns ; slit like , and occipital horns ; enlarged aka COLPOCEPHALY
Spina Bifida (OCCULTA)?
Closed defect
Skin surface abnormally noted on postnatal physical examination
Can be a sacral dimple, tuft of hair, hemangioma, or lipoma
Spina Bifida Aperta ?
typically an OPEN defect
AKA cystica
Mass may be referred to as ;
Meningocele or Meningomyelocele (depending upon contents)
Intracranial anatomy is often altered (lemon and banana sign)
The exposure of delicate spinal nerves to the amniotic fluid during fetal life is thought to be one of the causes of neurologic impairment
Appearance of meningocele ?
Simple cystic mass protruding from the spine
Appearance of myelomeningocele ?
More complex
Scoliosis ?
Deformity of the spine where there is an abnormal lateral curvature
Spine will appear “S” shaped in the affected region (most common the thoracic and upper lumbar region)
Kyphosis ?
Abnormal posterior curvature of the spine
Can coexist with scoliosis - kyphoscoliosis
Distortion of the fetal spine can be seen with ?
Hemivertebrae, myelomeningocele, ABS/ amniotic band syndrome, and limb body wall complex
Often associated additionally with
VACTERL association
Limb body wall complex ?
Short umbilical cord
Rare group of fetal defects
Three speculated causes ;
Vascular occlusion, amnion rupture, or embryonic dysgenesis
LBWC sonographic features ?
Short/ or absent umbilical cord
(FATAL)
Ventral wall defects (elevated MSAFP)
Limb defects
Craniofacial defects
(Exencephaly or encephalocele) and
Scoliosis
ABS appears similar and usually detected within the second trimester
Skeletal Dysplasia ?
Most common skeletal dysplasias?
Achondroplasia
Achondrogenesis
Osteogenesis Imperfecta
Thanatophoric Dysplasia
Achondroplasia?
Heterozygous Autosomal Dominant
Most common non lethal skeletal dysplasia
Dwarfism of the proximal bones (humerus and femurs)
(A.K.A RHIZOMELIA)
Rhizomelia ?
Short length of proximal bones (femur and humerus)
Sonographic findings of achondroplasia ?
Notable difference in the gestational age measurements between the BPD and femur length (discovered typically mid / later second trimester)
Micromelia, macrocrania, frontal bossing, flattened nasal bridge, and TRIDENT hand
Homozygous achondroplasia ?
Usually fatal within the first two years of life
Can occur when both parents are dwarfs
Achondrogenesis ?
Rare and LETHAL condition resulting in absent mineralization of bones (cranial/ skeletal)
(Ossification deficiency)
Suffer from severe limb shortening and have rib fractures
Ultimately leading to stillbirth or early death
Sonographic findings of Achondrogenesis ?
Large skull
Severely shortened limbs
Demineralization of fetal skull and skeleton
Distention of the abdomen and narrowing of the chest
Polyhydramnios is often present
Osteogenesis Imperfecta?
Brittle bone disease, results in multiple fractures that can occur in utero — resulting from the decreased mineralization and poor ossification
Type 2 ; most severe form/ lethal
Types ; 1, 3 & 4 are typically diagnosed after birth
Most severe form of osteogenesis Imperfecta ?
TYPE 2
Results in multiple fractures in utero, skull demineralization (lack of shadowing posteriorly), bell shaped chest, and lack of movement
Most common lethal skeletal dysplasia ?
Thanatophoric Dysplasia
Thanatophoric Dysplasia ?
Most common lethal skeletal dysplasia
Cloverleaf skull shape with frontal bossing and hydrocephalus
Shortened LONG bones have a “telephone receiver” shape
Thoracic and abdominal circumference will be remarkably dissimilar — leading to BELL shaped chest —- which results in hypoplasia of the lungs
(Best seen in a sagittal view of the fetus)
Most fetus die shortly after birth due to respiratory distress resulting from pulmonary hypoplasia
Caudal Regression Syndrome?
AKA sacral agenesis
Absence of sacrum or coccyx
May also be defects in the lumbar spine and lower extremities
Strong association with uncontrolled maternal pregestational diabetes
Sirenomelia?
Mermaid syndrome because of the fusion of the lower extremities
Bilateral renal agenesis is associated with this syndrome making it LETHAL
Associated with uncontrolled maternal pregestational diabetes
Sirenomelia sonographic findings ?
Due to bilateral renal agenesis there will be oligohydramnios present
Cardiac anomalies
Two vessel cord
Genital absence
SCT / Sacrococcygeal Teratoma ?
Germ cell tumor
Most common congenital neoplasm and frequently found in females
Typically appear as complex or solid mass extending posteriorly and inferiorly from the distal fetal spine
May cause obstruction of the urinary tract and destruction of the sacrum and pelvic bones
LARGER SCTs have malignant potential
Associated with hydrops and may lead to high output congestive heart failure
Axial skeleton consists of ?
Cranium and spine
Appendicular skeleton consists of ?
Upper / lower extremities
Pelvic bones
Upper extremities consist ?
Phalanges / fingers
Metacarpals
Carpals
Radius
Ulna
Humerus
Clavicle
Scapula
Lower extremities consist of ?
Phalanges/ toes
Metatarsals
Tarsals
Tibia
Fibula
Femur
Fetal long bones can be measured from what gestation week?
Early as 12 weeks gestation
Acromelia?
Shortening of the distal segment of a limb
Radial Ray defect ?
Absent or hypoplastic radius
Can be seen in the presence of trisomy 13, trisomy 18, cardiac abnormalities, and VACTERL association
Talipes?
Clubfoot
Malformation of the bones of the foot
Most often inverted and rotated Medially
Metatarsals and toes lie in the same plane as the tibia and fibula
Limb reduction associated with ?
ABS / amniotic band syndrome
These bands can entrap fetal parts, and cause amputation of digits, limbs, and even the skull
Fetal heart sonographic findings ?
Begins to contract 35 days of gestation
Sonographically M-mode heart motion reading can be obtained when the CRL is 4 to 5 mm length
Fully formed by 10 weeks
Heart fills one - third of the fetal chest, with a 45 degree formed with the apex of the heart and spine
Closest heart chamber closest to the fetal spine ?
Left Atrium
Atrium septum opening AKA ?
Foramen ovale
Valve between the right atrium and right ventricle ?
Tricuspid valve
Valve between the left atrium and left ventricle ?
Mitral valve
Which heart valve is closer to the cardiac apex ?
Tricuspid > Mitral valves
RVOT?
Leads to the pulmonary artery and branches
LVOT?
Leads to the Aorta
(Pulmonary artery should be seen anterior to the aorta / crossing over it / the aorta and pulmonary artery criss cross eachother)
Umbilical cord contents ?
Two umbilical arteries
Umbilical vein
Wharton jelly
Umbilical cord contents ?
Two umbilical arteries
Umbilical vein
Wharton jelly
Umbilical Arteries function ?
Return deoxygenated blood from the fetus back to the placenta
Umbilical Vein function ?
Brings oxygen - rich blood from the placenta to the fetus
Fetal circulation ?
The existing oxygen-rich blood in the IVC travels up to the heart and enters the right atrium. Blood can then travel across the foramen ovale, an opening in the lower middle third of the atrial septum and into the left atrium, or it can enter the right ventricle through the tricuspid valve. The blood then leaves the right ventricle through the main pulmonary artery. The main pulmonary artery bifurcates into right and left, thus allowing a small amount of blood to travel to the respective lung. Blood from the right ventricle can also flow through the ductus arterious and into the descending aorta
The blood returning from the lungs through the pulmonary veins enters into the left atrium. Blood then travels from the left atrium into the left ventricle via the mitral valve. From the left ventricle, it travels to the ascending aorta and into the aortic arch, where it exits into the brachiocephalic artery, left common carotid artery, and left subclavian artery on its way to the thorax, upper extremities, and head. The blood will return from the head and upper torso via the superior vena cava to the right atrium.
The blood that flows through the ductus arteriosus and into the descending aorta travels inferiorly to either exit the abdomen via the umbilical arteries or travels to the abdomen and lower extremities to replenish those regions.
Therefore, the umbilical arteries return the deoxygenated blood from the fetus back to the placenta.
Hypoplastic LEFT heart syndrome?
Group of anomalies defined by small or absent left ventricle
Leading cause of cardiac death in the neonatal period
Anomaly can be recognized in a 4 chamber transverse image plane
To distinguish this anomaly — a small or normal left atrium must be visualized
Associated with Edwards syndrome and Turner’s syndrome when found in girls
Hypoplastic RIGHT heart syndrome ?
Small or absent right ventricle
Best seen in axial view of 4 chamber heart view
Most often results from pulmonary stenosis or pulmonary atresia
May result from stenosis or atresia or the tricuspid valve
Ventricular Septal Defects ?
Abnormal opening in the septum between the two ventricles
Most common form of cardiac defect
Can be isolated associated with chromosomal anomalies or other cardiac anomalies such as ; teratology of fallot
Colour doppler can be used to identify the flow within and through the defect
Most common form of cardiac defect ?
VSD/ ventricular septal defect
Atrial Septal Defects ?
Abnormal opening in the septum between the atrium of the heart
Can be isolated but may be found in the presence of various syndromes
Atrioventricular Septal Defects ?
Combination of atrial and ventricular septal defects
Results from abnormal development of the central portion of the heart / endocardial cushion
Endocardial cushion defect
Commonly associated with aneuploidy, trisomy 21 and trisomy 18
Ebstein anomaly ?
Malformation / malpositioning of the tricuspid valve
Right ventricle is contiguous with the right atrium
(“Atrialized” right ventricle)
Associated with ;
Tricuspid regurgitation, ASDs, tetralogy of fallot, transposition of great vessels, and coarctation of the aorta
Prognosis is poor with 80% dying within the perinatal period
Coarctation of the Aorta ?
Narrowing of the aortic arch
Most common location between the left subclavian artery and the ductus arteriosus
Associated finding consists of right ventricle and pulmonary artery enlargement
Other common findings includes ; patent ductus arteriosus and VSDs
Tetralogy of Fallot?
Defined as overriding aortic root, subaortic VSD, pulmonary stenosis, and right ventricular hypertrophy
Transposition of the great vessels?
Outflow tracts are reversed
Pulmonary artery abnormally arises from the left ventricle and the aorta abnormally arising from the right ventricle
Instead of the normal criss- cross orientation of the pulmonary artery and aorta — they instead will course parallel with the aorta anterior to the right pulmonary artery
Good prognosis if discovered in utero because corrective surgery can be done shortly after birth
echogenic intracardiac focus associated with ?
Trisomy 21 / Down’s syndrome but can also be seen in a normal fetus
Often seen in the left ventricle of the heart
Echogenicity of the EIF is comparable to that of fetal bone
Thought to represent the calcification of the papillary muscle or chordae tendinae
Rhabdomyoma?
Most common fetal cardiac tumor
Found within the myocardium
Associated with tuberous sclerosis, eventual cardiac failure, and subsequent development of the fetal hydrops
Typically appear as echogenic and may be isolated or multiple
Pericardial Effusion ?
Fluid located around the heart
Can be isolated or associated with fetal hydrops
Ectopic Cordis?
Heart is either partially or completely located outside the chest cavity
(Associated with pentalogy of Cantrell which includes a coexisting omphalocele )
Prognosis is poor
Fetal lung development ?
Functional fetal lung development tissue doesn’t typically exist until after 25 weeks
Fetal lung maturity can be assessed using the L;S ratio (lecithin/ sphingomyelin)
Normally lungs that are maturing have increased levels of lecithin, whereas the sphingomyelin levels decrease
Pulmonary Hypoplasia ?
Underdevelopment of the lungs
Caused by decreased number of lung cells, airways, and alveoli
Often associated with major structural and chromosomal abnormalities
Diaphragmatic hernia is the most common lesion associated with pulmonary hypoplasia
Little or no amniotic fluid puts the fetus an increased risk of pulmonary hypoplasia
Associated with oligohydramnios and potters syndrome
Potters syndrome ?
Oligohydramnios —
Pulmonary Hypoplasia
Bilateral renal agenesis
Abnormal facial features
Limb abnormalities
IUGR
Pleural effusion?
Fluid surrounding the lungs
Occurs in utero may spontaneously resolve, or may be found in the presence of fetal hydrops, other chest abnormalities and Turners Syndrome
UNILATERAL or BILATERAL involvement
Appears as anechoic fluid surrounding the fetal lung
BATWING sign
Bat wing sign ?
Pleural effusion
Cystic Adenomatoid Malformation (C/CAM)
Mass consisting of abnormal bronchial and lung tissue
Mass that has both solid and cystic components
It can also appear as completely echogenic
Sonographically similar to pulmonary sequestration
Most are unilateral and may resolve spontaneously,
Larger masses can lead to fetal hydrops and carry a poor prognosis
Pulmonary sequestration?
Separate mass of nonfunctioning lung tissue with its own blood supply
Appears as a echogenic triangular shape mass
Typically seen on the LEFT side of the fetal chest
May resolve spontaneously or lead to development of fetal hydrops
Diaphragmatic hernia
Bochdalek / Morgagni (Rt/ Lt)
Most common reason for fetal cardiac malposition
Malposition of the fetal heart as a result of the stomach or other abdominal organs being located within the chest
Results in an abdominal contents being herniated into the chest cavity
Right sided/Morgagni defects of the diaphragm are harder to detect because the liver and lungs echogenicity appears similar / isoechoic
Bochdalek Hernia ?
Left sided hernia
Resulting in the left liver, stomach and bowel found within the chest instead of the abdomen
Foramen Morgagni ?
Right diaphragmatic hernia that causes the whole liver to herniate into the chest cavity
Harder to detect RIGHT side hernia than left / Bochdalek
Eventration of the diaphragm ?
Lack of muscle within the dome of the diaphragm
Appears similar to diaphragmatic hernia
Digeorge syndrome ?
Genetic disorder defined by absent or hypoplastic thymus
Which ultimately leads to impairment of the immune system and susceptibility to infection, as well cognitive disorders, congenital heart defects, palate defects, and hormonal abnormalities
What is described as the absence of the pulmonary valve, which in turn prohibits blood flow from the right ventricle into the pulmonary artery and essentially to the lungs?
a. Pulmonary atresia
b. Pulmonary stenosis
c. Pulmonary sequestration
d. Pulmonary effusion
Pulmonary Atresia
All of the following are sonographic signs of Ebstein anomaly except:
a. Enlarged right atrium
b. Fetal hydrops
c. Narrowing of the aortic arch
d. Malpositioned tricuspid valve
Narrowing of the aortic arch ?
What is an opening within the septum that separates the right and the left ventricles?
a. Endocardial cushion
b. Tricuspid regeneration
c. VSD
d. ASD
VSD
The narrowing of the aortic arch is indicative of:
a. Tetralogy of Fallot
b. Coarctation of the aorta
c. Ebstein anomaly
d. Hypoplastic right heart syndrome
Coarctation of Aorta
All of the following are sonographic features of pentalogy of Cantrell except:
a. Omphalocele
b. Gastroschisis
c. Cleft sternum
d. Diaphragmatic defect
Gastroschisis
What is the fetal shunt that connects the pulmonary artery to the aortic arch?
a. Foramen ovale
b. Ductus arteriosis
c. Ductus venosis
d. Foramen of Bochdalek
Ductus Ateriosis
The moderator band is located within the:
a. Right atrium
b. Left atrium
c. Right ventricle
d. Left ventricle
Right Ventricle
The most common cause of cardiac malposition is:
a. Diaphragmatic hernia
b. Omphalocele
c. Gastroschisis
d. Pulmonary hypoplasia
Diaphragmatic Hernia
The most common sonographic appearance of pulmonary sequestration is a(n):
a. Dilated pulmonary artery and hypochoic chest mass
b. Pleural effusion and ipsilateral hiatal hernia
c. Triangular, echogenic mass within the chest
d. Anechoic mass within the chest
Triangular, echogenic mass within the chest
Tetralogy of Fallot consists of all of the following except:
a. Overriding aortic root
b. VSD
c. Pulmonary stenosis
d. Left ventricular hypertrophy
Left ventricular hypertrophy
Which statement is true concerning fetal outflow tracts?
a. The normal pulmonary artery should be positioned posterior to the aorta and should be visualized passing under it.
b. The normal pulmonary artery should be positioned anterior to the aorta and should be visualized crossing over it.
c. The right ventricular outflow tract leads to the aorta.
d. The left ventricular outflow tract leads to the pulmonary artery.
The normal pulmonary artery should be positioned anterior to the aorta and should be visualized crossing over it
What is the normal opening in the lower middle third of the atrial septum?
a. Foramen of Magendie
b. Foramen of Monro
c. Foramen ovale
d. Ductus arteriosus
Foramen Ovale
What structure shunts blood into the IVC from the umbilical vein?
a. Ductus venous
b. Ductus arteriosus
c. Foramen ovale
d. Foramen of Luschka
Ductus Venosus
Which of the following is not a true statement about the normal fetal heart?
a. The ventricular septum should be uninterrupted and of equal thickness to the left ventricular wall.
b. There is a normal opening within the atrial septum.
c. Between the right ventricle and the right atrium, one should visualize the tricuspid valve.
d. The mitral valve is positioned closer to the cardiac apex than the tricuspid valve.
The mitral valve is positioned closer to the cardiac apex than the tricuspid valve.
The blood returning from the lungs through the pulmonary veins enters into the:
a. Right atrium
b. Left atrium
c. Right ventricle
d. Left ventricle
Left Atrium
A coexisting pericardial effusion and a pleural effusion is consistent with the diagnosis of:
a. Tetralogy of Fallot
b. Pentalogy of Cantrell
c. Fetal hydrops
d. Potter syndrome
Fetal Hydrops
Which of the following best describes transposition of the great vessels?
a. The aorta arises from the left ventricle, and the pulmonary artery arises from the right ventricle.
b. The aorta arises from the right ventricle, and the pulmonary artery arises from the left ventricle.
c. The aortic arch is narrowed and positioned anterior to the pulmonary vein.
d. The presence of an omphalocele and ectopic cordis.
The aorta arises from the right ventricle, and the pulmonary artery arises from the left ventricle.
Sonographic findings of fetal GI tract ?
Stomach can be seen by 8 weeks and should be seen by 14 weeks gestation
AC can be used in AXIAL view to measure the abdominal circumference from the second trimester
(At the level including stomach, umbilical vein, and thoracic spine)
Differentiation between the bowel and colon can be done in the later gestational ages and the colon will demonstrate larger loops and contains hypoechoic material representing meconium
Polyhydramnios results from?
Obstruction or disruption of the normal flow and absorption of amniotic fluid such as ;
Esophageal atresia and duodenal atresia
Esophageal Atresia ?
Congenital absence of part of the esophagus
Stomach may appear small or completely absent
With polyhydramnios present
Associated with;
VACTERL association, Tracheoesophageal fistula, Down syndrome / 21, IUGR, trisomy 18/ Edwards
Duodenal Atresia?
Congenital maldevelopment or absence of the proximal portion of the small bowel
Dilated, anechoic fluid - filled stomach and proximal duodenum
(DOUBLE BUBBLE sign)
Associated with;
Trisomy 21, esophageal atresia, VACTERL association, IUGR, and cardiac anomalies
Fetal liver sonographic findings?
Most common abnormality of the fetal liver
Intrauterine infections, fetal Rh anemia, and Beckwith Wiedemann syndrome
Choledochal cyst can lead to ?
Cystic dilation of the common bile duct
Cholangitis, portal hypertension, pancreatitis, and liver failure
Echogenic bowel ?
Echogenicity of the small intestine should NOT be isoechoic or greater than fetal bone
Linked to ;
Down syndrome, cystic fibrosis, growth restriction, fetal demise, congenital infections; cytomegalovirus and gastrointestinal obstructions
Hirschsprung disease ?
Causes the functional fetal bowel obstruction caused by the absence of nerves within the bowel wall
Dilated loops of bowel within the fetal abdomen
Most common type of colonic atresia leading to bowel obstruction?
Anorectal atresia
Anorectal atresia?
Most common type of colonic atresia leading to bowel obstruction
Causes dilation of the bowel and rectum
May be associated with VACTERL association, chromosomal abnormalities
Gastroschisis ?
Herniation of abdominal contents through a RIGHT periumbilical abdominal wall defect
Most often herniation of the small intestines but with larger defects the stomach and other organs may herniate
May suffer from intrauterine growth restriction / IUGR
Seeing loops of bowel often noted outside the fetal abdomen floating in the amniotic fluid
Omphalocele ?
Persistent herniation of the bowel
Located within the midline of the abdomen
Umbilical cord will insert into the “mass” contained by peritoneum and amnion
Ascites is noted within the “mass” and within the fetal abdomen
Important to assess whether the liver is within the omphalocele since it corresponds with a poor prognosis
Has a more significant risk of heart defects and chromosomal anomalies than gastroschisis
Associated with ;
Trisomy 18, trisomy 21, trisomy 13, Beckwith Wiedemann syndrome and Turner’s syndrome also Pentalogy of Cantrell
Pentalogy of Cantrell?
Associated with a group of the following anomalies ;
Ectopic cordis
Cleft sternum
Diaphragmatic defect
Pericardial defects
Omphalocele
Pentalogy of Cantrell includes all of the following findings except:
a. Cardiovascular malformations
b. Diaphragmatic malformations
c. Omphalocele
d. Gastroschisis
Gastroschisis
All of the following are associated with omphalocele except:
a. Trisomy 18
b. Pentalogy of Cantrell
c. Intrauterine growth restriction
d. Hirschsprung disease
Hirschsprung disease
All of the following are associated with gastroschisis except:
a. Normal cord insertion
b. Multiple chromosomal abnormalities
c. Elevated MSAFP
d. Periumbilical mass
Multiple chromosomal abnormalities
What is an inherited disorder in which mucus secreting organs such as the lungs, pancreas, and other digestive organs produce thick and sticky secretions instead of normal secretions?
a. Hirschsprung disease
b. Cystic fibrosis
c. Multiple sclerosis
d. Turner syndrome
Cystic fibrosis
Duodenal atresia and esophageal atresia are associated with:
a. Oligohydramnios
b. Polyhydramnios
c. Normal amniotic fluid index
d. Anhydramnios
Polyhydramnios
Intrauterine growth restriction is defined as:
a. A small-for-dates fetus
b. A fetus that falls below the 10th percentile for gestational age
c. A fetus that is immunocompromised and has decreased umbilical cord
Doppler ratios for gestational age
d. A fetus that fall below the fifth percentile for gestational age
A fetus that falls below the 10th percentile for gestational age
Fetal stool is termed:
a. Plicae
b. Meconium
c. Laguna
d. Lanugo
Meconium
All of the following are associated with omphalocele except:
a. Normal cord insertion
b. Multiple chromosomal abnormalities
c. Elevated MSAFP
d. Periumbilical mass
Normal cord insertion
An omphalocele may contain:
a. Fetal liver
b. Ascites
c. Fetal colon
d. All of the above
All of the above
Which of the following would be most likely associated with
oligohydramnios?
a. Duodenal atresia
b. Hepatomegaly
c. Bilateral renal agenesis
d. Physiologic bowel herniation
Bilateral renal agenesis
All of the following are sonographic findings of esophageal atresia except:
a. Absent stomach
b. Polyhydramnios
c. Macrosomia
d. Intrauterine growth restriction
Macrosomia
Fetal kidneys sonographic findings ?
Ascend within the abdomen from the pelvis where they initially develop within 9 weeks
Can be sonographically identifiable by TA in12 weeks and TV by 11 weeks
Renal abnormalities are the most common cause of oligohydramnios
Around 9 weeks the fetal kidneys begin to produce urine and comprise the greater part of the amniotic fluid volume after 14 weeks
Most common renal anomaly ?
Duplex collection system (upper/ lower moiety)
Fetal testicles ?
Descend from the fetal abdomen where they initially develop and then descend into the pelvis, during the seventh month the testicle descend into the scrotum
Fetal bladder?
Seen as early as 12 weeks and should consistently be seen by 15 weeks
Normal fetal ureters are not normally seen sonographically
Fetal adrenal gland appearance?
Triangular hypoechoic shape structure superior to the upper pole of the kidneys
VACTERL association?
Vertebral anomalies
Anal atresia
Cardiac anomalies
Trachoesophageal fistula or esophageal atresia
Renal anomalies
Limb anomalies
Horseshoe kidneys ?
Isthmus connecting the lower pole of the kidneys anterior to the aorta and IVC congenital anomaly
Oligohydramnios associated with ?
Bilateral renal agenesis,
Inadequately functioning kidneys,
Or obstruction of the urinary tract
Most worrisome consequence of oligohydramnios ?
Pulmonary hypoplasia / underdevelopment of lungs
Bilateral renal agenesis?
Associated with Potters syndrome, Sirenomelia, and various cardiovascular malformations
Sonographic findings includes;
Nonvisual of the kidneys and bladder with associated severe oligohydramnios
Unilateral renal agenesis ?
Much more common than bilateral
Normal amount of amniotic fluid present
Prognosis is good
Compensatory Hypertrophy present (contralateral kidney enlarges and does the job of both kidneys)
Most common location of an ectopic kidney ?
Pelvis
Fetal renal cystic disease types?
Autosomal Recessive Polycystic Kidney Disease (ARPKD)
Autosomal Dominant Polycystic Kidney Disease
(ADPKD)
Multicystic Dysplastic Kidney Disease (MCDK)
Obstructive cystic dysplasia
ARPKD
Autosomal Recessive Polycystic Kidney Disease?
INFANTILE
Appears as bilateral enlarged echogenic kidneys with microscopic cysts that are not able to be distinguished between on sonography
The kidneys can be enlarged up to 3 to 10 times the average size
ARPKD sonographic findings ?
Enlarged echogenic kidneys with multiple microscopic cysts
Oligohydramnios
Absent bladder
ARPKD is associated with?
Meckel Gruber Syndrome
Trisomy 18 and Trisomy 13
(Bilateral enlarged echogenic kidneys, absent urinary bladder and oligohydramnios present)
Meckel Gruber Syndrome ?
Fatal disorder
Includes renal cystic disease, occipital encephalocele,and polydactyly
ADPKD ?
Adult polycystic kidney disease
Appears with a normal urinary bladder and amniotic fluid volume
Typically doesn’t manifest till fourth/ fifth decade of life will develop renal cysts and may die from end stage renal failure
Associated with development of cysts within the liver, pancreas, and spleen
MCDK ?
Multicystic Dysplastic Renal Disease
Thought to be caused by an early first trimester obstruction of the ureter
Appears;
Unilateral / Bilateral multiple, smooth - walled, noncommunicating cysts of varying sizes in the area of the renal fossa
No normal functional renal tissue will be present typically in the affected kidney
(Disease is mostly UNILATERAL)
Associated with additional gastrointestinal tract, central nervous system, limb, and further renal anomalies
MCDK bilateral sonographic findings?
Bilateral smooth walled noncommunicating cysts of varying sizes in the area of the renal fossa
No normal functioning renal tissue present typically in affected kidneys — hence prognosis is poor and fatal
Associated with oligohydramnios and absent bladder
Unilateral obstructive cystic dysplasia ?
Most often caused by a pelviureteral junction or vesicoureteral junction obstruction
Bilateral obstructive cystic dysplasia ?
Caused by severe bladder outlet obstruction early in gestation
May also be associated with urethral atresia or posterior urethral valves
Obstructive cystic dysplasia sonographic findings ?
Kidneys appear small and echogenic and have peripheral cysts along its margins
There will be also evidence of hydronephrosis and a thick walled bladder wall
UVJ?
Ureter meets the bladder
Leading to dilation of the ureter, renal pelvis and calices
UPJ ?
Renal pelvis meets the ureter
Renal pelvis and calices will be dilated
The ureter and bladder will appear most likely normal
Most common fetal abnormality?
Hydronephrosis
Renal pelvis AP diameter should not exceed before 20 weeks ?
< 7 mm
Renal pelvis AP diameter should not exceed after 20 weeks ?
< 10 mm
Most common areas where obstruction occurs?
UPJ
UVJ
Urethra
Less common causes of hydronephrosis ?
Ureterocele
Ectopic ureter
Vesicoureteral reflux
Urethral atresia
Ureteropelvic junction obstruction ?
Most common cause of fetal hydronephrosis and most common form of fetal renal obstruction
Commonly unilateral and more common seen in men
Causes dilation of the renal pelvis and calices
Fetal pyelectasis can be a sonographic marker for Down Syndrome / Trisomy 21
most common cause of fetal hydronephrosis ?
UPJ obstruction
Bladder outlet obstruction ?
Blockage of flow of urine exiting the urethra
Significant to determine gender of fetus (since posterior urethral valves are a common cause in MALES)
Posterior Urethral Valve obstruction ?
Keyhole sign
Dilation of the bladder and the posterior urethra
Result in dilation of the bladder, ureters, and renal collecting system
Oligohydramnios and bladder wall thickening will be noted as well
Prune Belly Syndrome ?
Typically caused by megacystis
MALE INFANTS
Results in abdominal wall musculature being stretched by the extremely enlarged urinary bladder
Result of a urethral abnormality which in turn leads to bladder outlet obstruction
KEYHOLE sign
There will be eventual dilation of the ureters and renal collecting systems
TRIAD of prune belly syndrome ?
Absent abdominal musculature
Undescended testicle
Urinary tract abnormality
Ureteropelvic junction obstruction?
Least common cause of fetal hydronephrosis
The renal collecting system
and ureter will be dilated
If unilateral will have normal amniotic fluid
But if BILATERAL — will have oligohydramnios
Bladder Exstrophy?
Bladder is located outside the pelvis
Signs ;
No visual of bladder in the presence of normal amniotic fluid volume and normal kidneys
Lower abdominal wall mass inferior to the umbilicus
OEIS complex ?
Omphalocele
Bladder Exstrophy
Imperforate anus
Spina BifIda
Most common fetal solid renal mass?
Mesoblastic Nephroma
Mesoblastic Nephroma?
Most common fetal solid renal mass
Aka hamartoma of kidney
Appears as solid, homogenous mass within the renal fossa and may completely replace the kidney, and may contain cystic components
XX?
Female
XY?
Male
Ambiguous Genitalia?
Birth defect in which the sex of the fetus cannot be determined
Hypospadias ?
Abnormal ventral curvature of the penis as a result of shortened urethral that exits on the ventral penile shaft
Most common fetal malignant abdominal mass?
Neuroblastoma
(Primarily located within the adrenal gland)
Multiple gestation may present ?
Clinically large for dates and elevated hCG levels compared to a singleton
Association with higher risk of multiple gestations occurring ?
Maternal history of multiple gestations
ART
OVULATION INDUCTION therapy / drugs
Advanced maternal age
Maternal obesity
ART and ovulation induction drugs are assoicated with multiple gestations and ?
Heterotopic pregnancy
Monozygotic twin?
Arise from a single zygote
Dizygotic twins ?
Arises from 2 separate zygotes
Chorion?
Structure that forms the placenta,
Develops before the amnion
Relates to how many placentas are present
Twins share placenta ; Monochorionic
Twins have own individual placentas ;
Dichorionic
Amnionicity?
How many amniotic sacs present
Monoamniotic ; single
Diamniotic ; twins have own individual amniotic sac
Dizygotic Twins ?
Most common form of twins
( arise from two separate fertilized ova )
Fraternal twins ( Dichorionic & Diamniotic )
( 2 placentas / 2 amniotic sacs )
( However in early gestation the placentas may appear “fused” and appear as one large placenta with sonography )
Monozygotic Twins ?
Arise from one single zygote
( Always IDENTICAL twins )
Amnioticity /chorionicity type depends on time of zygote division
Between 4 to 8 days ; monochorionic and diamniotic (most common form)
Before 4 days ; leads to dichorionic and diamniotic
Late split beyond 8 days ; leads to monochorionic and monoamniotic
Most common type of monozygotic twins?
Least probable type of monozygotic twins ?
Least probable type of monozygotic twins ?
Monochorionic and monoamniotic twin
Types of monozygotic twins ?
Dichorionic / diamniotic
Dichorionic / monoamniotic
Monochorionic / Monoamniotic
Additional risk of conjoined twins?
Monoamniotic ( twins that share an amniotic sac )
Monochorionic & Monoamniotic twin ?
Late split of zygote leading to twin sharing a placenta and amniotic sac
Which increases the risk of conjoined twins occurring (monoamniotic)
Monochorionic & Diamniotic twin ?
Most common type of monozygotic twin
Zygote division occurs 4 to 8 days
Share a placenta but have own amniotic sacs
(When twins share a placenta, complications are more likely to occur)
Dichorionic & Diamniotic twin ?
Earlier division of zygote before 4 days
Leads to 2 separate amniotic sacs and placentas
8th week trimester scan reveals a single yolk sac and two embryos present indicative of ?
Monoamniotic twins
Two yolk sacs presents with two embryos in a 8th week scan indicative of ?
Diamniotic twins
Sonographic sign of dichorionic and diamniotic twins present ?
Lambda sign / twin peak sign
Triangular extension of the placenta at the base of the dividing membrane
Sonographic signs of Monochorionic and Diamniotic twin pregnancy ?
Membrane will be small and thin at the junction point of the placenta
T- sign
Determining what can be more indicative of twins being dichorionic ?
Different genders
Same gender twins have a single placenta and a thin membrane separating them almost certainly indicative of monochorionic
Twin to Twin Transfusion ?
Complication that carries a high mortality rate for monochorionic TTTs
Recipient / donor twin
Sonogram will reveal discordant growth
Associated with stuck twin / donor
Donor twin regarding TTTs ?
Twin shunts blood to the other
Often suffer from anemi and growth restriction
May be the stuck twin suffering from oligohydramnios
More likely to survive out of the two twins and associated with fetus sharing a placenta
Recipient twin regarding TTTs ?
Experience hydrops and congestive heart failure
Enlarged fetus, most likely to die out of the two twins
Polyhydramnios present
Acardiac twin ?
Abnormal anastomoses of placental vessels may result, also considered to a severe form of TTTs
Aka ; TRAP (twin reversed arterial perfusion)
One normal fetus / pump twin and an abnormally developed fetus containing no heart
Pump twin typically has a 50% mortality rate secondary to polyhydramnios and prematurity
Sonographic signs of the Acardiac twin ?
Abnormally developed twin with no heart present
Might also be absence of the head, cervical spine, and upper limbs.
With severe hydrops present
Conjoined twins?
Can result from monochorionic / monoamniotic twins
Can be attached at the head, thorax, abdomen, and lower part of the body
Prognosis is typically poor, with 41% chance of being stillborn, with many dying within the first 24 hours
Craniopagus/ thoracogagus/ omphalopagus / ischiopagus / pyopagus
Craniopagus ?
Joined at head
Thoracopagus ?
Joined at the chest / thorax
Omphalopagus ?
Joined at the abdomen
Ischiopagus ?
Joined at the pelvis
Pyopagus ?
Joined at the sacral spine
(Back - to - back)
Vanishing twin ?
Death of a twin and subsequent reabsorption of the embryo during the first trimester
(When the demised twin is maintained throughout the pregnancy aka fetus papyraceous)
With dichorionic ; servings twin is rarely affected by the death of the other twin
HOWEVER ;
Death of monochorionic twin during the first trimester frequently leads to death of both twins eventually due to sharing a placenta and twin embolization syndrome
Twin embolization syndrome?
When the demised twin and alive twin share a placenta ; common vascular channels within the shared placenta
Demised twin products pass to the alive twin
Death of monochorionic twin during the second/ third trimester can lead to ?
Life threatening problems in the surviving twin
Twin embolization syndrome
Complication including especially central nervous system and renal anomalies / kidneys are affected in the surviving twin
(Hydrocephalus and Porencephaly are common findings in the surviving twin)
Triplet pregnancy ?
Can manifest with different combinations of amnionicity and chorionicity
(Trichorionic triamniotic or
Dichorionic triamniotic )
Increased risk of discordant growth, miscarriage, and perinatal death
Typically results from ovulation induction therapy and ART/ IVF
Amnionicity / chorionicity should be determined
Multifetal reduction procedure ?
May be done with ultrasound guidance when a needle punctures the fetal heart so they can selectively reduce the number of fetus in utero with a injection of potassium chloride (stops the heart)
Mother expecting multiple gestations have an increased risk of ?
Preeclampsia and anemia
Risk of preterm delivery with associated low birth rate , specifically before 32 weeks gestation
Often at birth suffer from pulmonary hypoplasia with episodes of hypoxia (which can lead small blood vessels to rupture within the fetal brain causing intracranial hemorrhage and possible irreversible neurologic complications or death)
What condition is pregnancy-induced maternal high blood pressure and excess protein in the urine after 20 weeks’ gestation?
a. Gestational diabetes
b. Preeclampsia
c. Porencephaly
d. Maternal mirror syndrome
Preeclampsia
What is a treatment that separates abnormal placental vascular connections between twins that are suffering from TTTS?
a. Cleavage-laser resection treatment
b. Endoscopic-guided laser photocoagulation
c. Endemic translocation of placental vessels
d. Circumvallate resection of shared placental vasculature
Endoscopic-guided laser photocoagulation
TRAP syndrome may also be referred to as:
a. TIRS
b. Vanishing twin syndrome
c. Twin embolization syndrome
d. Acardiac twinning
Acardiac twinning
Which of the following can occur as a result of dizygotic twinning?
a. Monochorionic diamniotic twins
b. Monochorionic monoamniotic twins
c. Dichorionic diamniotic twins
d. All of the above
Dichorionic diamniotic twins
Which of the following can occur as a result of monozygotic twinning?
a. Monochorionic diamniotic twins
b. Monochorionic monoamniotic twins
c. Dichorionic diamniotic twins
d. All of the above
All of the above
The demise of a twin can lead to the development of neurologic complications in the living twin as a result of:
a. Twin embolization syndrome
b. TITS
c. TRAP syndrome
d. Dichorionicity
Twin embolization syndrome
The demise of a twin can lead to the development of neurologic complications in the living twin as a result of:
a. Twin embolization syndrome
b. TITS
c. TRAP syndrome
d. Dichorionicity
Twin embolization syndrome
Medial bones ( radius or ulna / tibia or fibula )?
Tibia
Ulna
bones more lateral and smaller ( radius or ulna / tibia or fibula )?
Smaller and shorter are the fibula and radius
Placenta adheres directly to the uterine myometrium ?
Placenta accreta
Placenta tissue invades the myometrium ?
Placenta increta
Placenta tissue completely invades the myometrial tissue and uterine wall?
Placenta percreta
Sonographic findings associated with fetal demise ?
Absent fetal heartbeat
Absent fetal movement
Overlapping of skull bones / Spaldings sign
Gas in fetal abdomen
Exaggerated curvature of the fetal spine
Battledore / marginal placenta ?
Less than 2 cm from the placental margin where the umbilical cord inserts within the placenta
Velamentous cord insertion ?
Umbilical cord inserts into the fetal membranes and travels to the placenta via the membranes
Majority of umbilical cord insertion site of placenta is typically ?
More than >3 cm from the margin of the placenta
Vasa previa ?
When large fetal vessels run in the fetal membranes (velamentous) across the cervix internal os
High risk of rupture and hemorrhage
Placenta ?
Seen early as 8 weeks developing
After 20 weeks of gestation lacunae lakes and calcifications will start to develop within the placenta
2 to 3 cm width after 23 weeks is average, thickness of placenta will rarely exceed 4 cm
enlarged placenta is associated with ?
TORCH infections
Diabetes
Hydrops
Congenital anomalies
Smaller placenta associated with ?
IUGR
Intrauterine infection
Aneuploidy
What part of the placenta is in contact with the myometrium ?
Basal surface
What part of the placenta can be seen along the exposed surface / fetal side ?
Chorionic plate
Thermal index should be less than / equal to ?
<1.0
Uterine artery flow in first trimester ?
High resistance
Uterine artery flow after the first trimester ?
Low resistance
Notched appeance in early diastole, disappears by 24 weeks
Placentomegaly ?
Over 600g weight
Appears abnormally thick ; AP > 4 cm
primary causes of Placentomegaly ?
Maternal diabetes
Fetal hydrops
Beckwith - Wiedemann syndrome
Placenta previa ?
Placenta implantation over internal os of cervix
Low lying placenta is diagnosed when the placenta edge is what distance away from the internal os of the cervix ?
Within 2 cm from the internal os of the cervix
Low lying placenta is diagnosed when the placenta edge is what distance away from the internal os of the cervix ?
Within 2 cm from the internal os of the cervix
Circumvallate placenta ?
Attachment of the placenta membranes to the fetal surface of the placenta rather than the underlying villous placenta margin
Placenta function?
umbilical vein transports oxygenated blood from the placenta to the fetus and the umbilical arteries return deoxygenated blood from the fetus to the placenta
(Reverses after birth)
Kleeblatschadel skull ?
Cloverleaf shape
Associated with thanatophoric dysplasia & ventriculomegaly
