Abnormal first trimester Flashcards
What are the different types of miscarriage?
Missed miscarriage - Asymptomatic with miscarriage criteria met
Miscarriage in progress - Symptomatic with
miscarriage criteria met
Complete miscarriage - Miscarriage with uterus/endo appearing normal
Patient presentation for subchorionic bleed?
Pelvic pain/abdominal pain
Perivaginal bleeding
Etiology of subchorionic bleed?
Separation of chorionic membranes from uterus wall caused by:
Uterine malformation
Hx of recurrant pregnancy loss
Pelvic infections
Miscarriage causes
Congenital anomalies
Luteal phase defect, where the corpus luteum fails to supply necessary hormones for development
Ectopic pregnancy presentation
Pain
Abnormal vaginal bleeding
Palpable adnexal mass
Haemodynamic instability
Triad = Amenorrhea, adnexal tenderness and cervical motion tenderness
Risks of ectopic pregnancy?
- Tubal abnormalities
- Previous tubal ectopic
- Reconstructive surgery
- Pelvic inflammatory disease
- Intrauterine device
- Increased maternal age
- Increased parity
- Previous c-section
- IVF pregnancy
Blood test indicator for ectopic pregnancy?
> 2000 = expect visible gestational sac
Ectopic pregnancy has suboptimal rise in bHCG
Types of ectopic pregnancy?
- Ampulla/isthmus of fallopian tube 95%
- Interstitial
- Within rudimentary horn
- Cervical
- C-scar
- Ovarian
- Intraabdominal
C-scar ectopic presents with what differentiating clinical sign?
Painless vaginal bleeding
Gestational Trophoblastic Disease presentation? (Hydatidiform molar pregnancy)
Spectrum of cellular diseases originating from placental villous trophoblast. Presents with:
- Abnormal vaginal bleeding
- Rapid uterine enlargement
- Large for dates
- Pregnancy induced HTN
- Hyperemesis gravidarum
- Preeclampsia
- Hyperthyroidism
Risks/etiology of GTD
- Young maternal age
- Advanced maternal age
- Previous molar pregnancy
- Multiple previous spontaneous abortions
Persistent Trophoblastic Neoplasia (PTN) types?
In order of likelihood:
1. Invasive mole
2. Choriocarcinoma
3. Placental site trophoblastic tumor
Risk factors of PTN?
- Molar pregnancy (complete = highest risk)
- > 40 years old
- Multiple molars
- Spontaneous abortion
- Ectopic (rare)
Clinical indicators of PTN?
- Vaginal bleeding
- Persistent bHCG elevation 1-3 months post-evacuation
- Amenorrhea
What is the role of bHCG in early pregnancy management?
- Initial detection
- Prognosis correlated with expected bHCG for gestational age
- Threshold level = level where gestational sac should be seen
- Discriminatory level = level at which absence of gestational sac can mean negative outcome
Clinical history for first-trimester pregnancy?
- Any abnormal vaginal bleeding
- Any abnormal pelvic/abdominal pain
- Date of last period (LMP)
- Regular periods?
- Previous c-section?
- IVF transfer date
- bHCG levels/trend
Concerning sonographic appearance of early pregnancy failure
- Embryo crl <7mm no heartbeat
- MSD 16-24mm with no embryo
- Gest sac low
- Gest sac irregular
- weak decidual reaction
- weakly echogenic trophoblast
- Low amniotic fluid (early oligo)
- Expanded amnion
- Yolk sac >6mm
- Calcified yolk sac
- Embryonic bradycardia/arrhythmia
- Large subchorionic hemorrhage (>50% gestational sac diameter).
RPOC sonographic features
- Thickened endometrial echo complex (EEC) >10mm
- Echogenic focus within endometrium
- Highly vascularised, with vascularity crossing myo/endo junction
- Heterogenous endometrial mass
Sonographic features of Subchorionic hemorrhage?
- Acute = hyper/iso fluid surrounding the decidua (>50% increases concern)
- Chronic = decreasing in echogenicity over time
- Extension of hematoma towards placental margin
Pregnancy of uknown location?
A positive bHCG test with no gestational sac seen in the uterus or adnexa with transvaginal ultrasound
Ectopic pregnancy sonographic features?
- Adnexal mass (heterogenous/solid)
- Moves separately to ovary
- Live extrauterine embryo
- Vascular ring
- Complex free fluid
- Empty endometrium
Ectopic pregnancy locations
- Cervical
- C-scar
- Interstitial
- Fallopian tube (ampulla most common)
- Ovarian
- Intra-abdominal
GTN sonographic features?
- Multicystic mass invading into myometrium
- Ill-defined endometrium
- Solid
- Uniformly echogenic, hypoechoic or complex/multicystic mass
- Thick walled anechoic areas with lesion/s (vascularity)
- Lobulated myometrium
- Marked hypervascularity
- Aliasing
- Chaotic vascular arrangement
Importance of assessing adnexa, uterus and ovaries in first trimester?
- Guides clinical management with correlation of bHCG
- Depending upon the location, size and progression of an ectopic, medical rather than surgical removal can be an option
- Fibroids can obstruct or compress important structures as pregnancy progresses depending upon size/location
- Ovarian cysts can affect pregnancy depending upon size (torsion etc.)
- Configuration of uterus can affect fertility and explain recurrent or likely miscarriage in the first trimester
- Postpartum it is important to check for RPOC, endometritis, GTN etc. in the symptomatic patient
Role of invasive diagnostic procedures in first trimester screening?
Primarily a test for chromosomal abnormalities
Can detect inherited genetic disorders
Chorionic villus sampling?
Ultrasound guided biopsy of chorionic villi. Used to determine chromosomes of baby.
11+2 - 13+6 weeks
Amniocentesis
15+ weeks
Ultrasound guided aspiration of amniotic fluid
NIPS
Maternal blood test
Used to screen for chromosomal abnormalities (T21, 13, 18)
Highest accuracy for down syndrome from 10+ weeks
Other syndromes screened:
1. Edwards syndrome
3. Patau syndrome
4. Angelman syndrome
Nuchal assessment parameters
> 3mm associated with aneuploidy (35%)
Reference value increases with age and therefore CRL is correlated with risk
NT >95% of average is considered thickened
Sonographic optimisation of nuchal measurement
- Focal zone optimisation
- Reduce dynamic range
- Reduce gain
- Harmonics off potentially
- Narrow sector
- No post freeze zoom
- Midsaggital plane of fetus, nose in profile, third and fourth ventricles of brain demonstrated
- Majority of image is occupied by fetus
- Head in neutral position, no extension/flexion
- Amnion seen separately from NT line
- Measure perpendicular to midsaggital plane
- Measure at the wides NT
- Crossbar of caliper at the inner border adjacent to lucency
Abnormalities seen within first trimester?
- Cystic hygroma
- Absent nasal bone
- Reversed A-wave in ductus venosus
- Tricuspid regurgitation
- Omphalocele
- Gastroschisis
- Alobar holoprosencephaly
- Mega cystitis
- Acrania
- Anencephaly
- Encephalocele
Cystic hygroma prognosis/management?
- Bilateral symmetrical cystic structures located in the occipital-cervical region
- Turner’s found in 50% of cases
- Hydrops is associated (60-80% of cases)
- Follow up scans every 4 weeks to assess progression of hygromas/hydrops
- 90% = fetal death. Other 10% have good prognosis if fetal karyotype is normal and hygromas resolve during pregnancy
Absent nasal bone prognosis/management?
- Absent nasal bone is associated with aneuploidy (T21 being most common)
- Other anatomical anomalies should be carefully screened for
- Prognosis dependent upon presence and severity of other anomalies.
- Good prognosis if isolated
Omphalocele prognosis/management?
- Should be screened for other anomalies
- Follow up scan every 4 weeks to monitor growth and amniotic fluid
- Isolated omphalocele has >80% survival rate
- If combined with other defects prognosis varies. Trisomy 18 is not compatible with life.
Gastroschisis prognosis/management?
- abdominal wall defect with evsisceration of bowel. Usually on the right side.
- Monthly ultrasound to monitor growth/liquor as well as dopplers and bowel dilatation.
- IUGR 30-60% of cases
- Survival >90%, main cause of death short bowel syndrome
Holoprosencephaly prognosis/management?
- lobar, semilobar and alobar holoprosencephaly
- Neurosonography and karyotyping necessary for chromsomal abnormality.
- MRI to confirm diagnosis
- Follow up ultrasound standard for continuing pregnancy
- Prognosis for alobar and semilobar is usually lethal within 1st year of life
- lobar holoprosencephaly life expectancy may be normal but with severe developmental delay/visual impairment.
Encephalocele management/prognosis?
- Trisomy 13/18 associated in 10% of cases
- Genetic syndromes found in >60% of cases
- Careful screening for other defects as well as karyotyping
- Caesarean section to avoid trauma to potential exposed brain tissue
- Prognosis depends on size, location and contents of encephalocele
- Mortality >50% in posterior encephalocele/meningocele and 20% in anterior encephalocele.
- Neurological handicap in >50% of survivors
- Sonographic follow up should be standard
Acrania prognosis/management?
- Absence of cranial vault leads to exencephaly
- Amniotic fluid destroys brain tissue resulting in anencephaly >16 weeks gestation
- CNS defects found in 50% of patients including spina bifida
- Standard follow up if pregnancy continues
- Not compatible with life, lethal within first week of life.
First trimester combined testing?
Is a combination of Nuchal translucency measurement and biochemical markers (NIPS):
1. Increases detection reliability
2. Can lead to invasive testing (chorionic villus sampling/amniocentesis) if positive.
Role of early anatomy assessment at 11-13 weeks?
- Not to be exhaustive.
- Looks for gross anomalies within the brain, face, spine, heart, abdomen, limbs and bladder.
Number of zygotes and their affect on type of twins?
Monozygotic twins = Zygote has split at a certain point and the twins will be identical
Dizygotic twins = Fraternal twins caused by two eggs + 2 sperm from 2 ovulations. These are always DCDA
Timing of split of monozygotic twins?
- DCDA = split <4 days
- MCDA = split at 4-7 days
- MCMA = Split at 7-14 days
- Conjoined twins = split >14 days
Clinical findings to raise suspicion of multiple gestations?
- hyperemesis gravidarum
- Larger uterus size for gestational age
- Higher HCG levels for dates
Higher likelihood of pregnancy caused by?
- Maternal family history
- IVF pregnancy
- Ovulation inducing drugs
- Increased maternal age
Role of ultrasound in multifetal 1st trimester scanning?
- Confirmation of chorionicity and amnionicity
- Confirmation of pregnancy location
- Assessment of ovarian cysts, fibroids etc. that may affect progression of pregnancy
Multifetal pregnancy in first trimester key information?
- CRL of largest twin for EDD
- Confirm chorionicity
- > 16 weeks = fortnightly scans for MCMA/MCDA
- Presence of intertwin membrane can be difficult to assess if early on (thin). Important to establish presence as this differentiates MCDA from MCMA.
