first trimester complications Flashcards
What is the most common occurrence of bleeding in the first trimester from?
Subchorionic hemorrhage
Signs of pregnancy failure
Severe pain, uterine contractions, dilated cervix
What percent of pregnancies spontaneously miscarry?
15%
What are the clinical findings of a subchorionic hemorrhage?
Bleeding, spotting, cramping (large enough will lead to spontaneous abortion)
Sonographic appearance of subchorionic hemorrhage
Later: anechoic between uterine wall and fetal membrane
Don’t cause bleeding or spotting because they are within the chorionic sac, without communication with the endometrium
Placenta hematomas
Empty uterus with no evidence of endometrial fluid collection, absence of adnexal masses and free fluid with positive beta-hCG levels
Absent intrauterine sac
Intrauterine sac should be identified when?
4.5 weeks
How fast does the gestational sac grow in the first trimester?
1 mm/day in first trimester
Yolk sac should be visualized when the gestational sac reaches what size?
8 mm
Embryo should be visualized when mean sac diameter is?
> 16 mm
Normal embryos grow how fast?
1 mm/day
Cardiac activity should be visible by when?
5.5-6.5 weeks (with hCG of 2000)
A thickened endometrium could be because of what?
Intrauterine blood, retained products of conception after incomplete spontaneous abortion, decidual reaction associated with pregnancy
Sonographic findings of a intaruterine sac after a spontaneous abortion
Intact gest sac to nonviable embryo to collapsed/mishapen gest sac
Sonographic signs of retained products
Thickende endo (>8mm) increased vascularization of endometrial complex with color doppler
Signs of a spontaneous abortion/retained products?
Visible embryonic parts/sacs, QhCG levels don’t decline normally, thickened endometrium with increased vascular flow
At what week should an embryo be seen?
6.4 weeks (6weeks3days)
Gestational sac where an embryo fails to develop or stops developing at such an early stage that it is imperceptible by ultrasound. Gest sac continues to grow along with trophoblastic tissue.
Blighted ovum or anembryonic pregnancy
Sonographic appearance of an anembryonic pregnancy
Large empty gestational sac with no yolk sac, amnion or embryo
Findings associated with abnormal IUP
Absence of cardiac motion after 6.5 menstrual weeks, large or calcified yolk sac, empty amnion, >18mm gest sac with no embryo, >8mm with no yolk sac, abnormmal shape and/or position of gest sac, absent or irregular trophoblastic reaction (<2mm), absent embryo/sac growth, hCG level discrepancy
Proliferative disease of trophoblast after abnormal conception
Trophoblastic disease
Occurs when an egg without a nucleus is fertilized by one sperm. Trophoblastic tissue proliferates but no fetal parts develop.
Complete hydatidiform moles
Occurs when a normal egg is fertilized by 2 sperm, fetal parts may develop but often aborted in 1st trimester. Has an identifiable placenta
Partial mole
Signs of gestational trophoblastic disease
Dramatically elevated beta-hCG levels, hyperemesis gravidarum, or preeclampsia, maternal serum AFP levels will be low
Sono appearance of gestational trophoblastic disease
distorted sac shape, thin, weakly echogenic decidual reaction, absence of double decidual sac, MSD=10mm
Malignant forms of gestational trophoblastic disease
Invasive mole and choriocarcinoma
Occurs when hydropic villi of a partial or complete mole invades uterine myometrium and may further penetrate uterine wall
Invasive hydatidiform mole
Signs/Symptoms of invasive moles
Continued heavy bleeding, very elevated hCG levels, enlarged uterus with multiple focal areas of grape-like clusters throughout
malignant form of trophoblastic disease that occurs in 2-3% of molar pregnancies.
Choriocarcinoma
Where does choriocarcinoma metastasize to?
Lungs, liver and brain
First conclusive sign of viability
Cardiac activity
When should cardiac activity be seen by?
5.5-6.5 weeks and hCG 2000 and embryo measures 4mm
If gestational sac in 5mm less than CRL what can be suspected?
Oligohydraminos
Yolk sac should grow how much per day?
0.3 mm/day
Yolk sac maximum diameter?
5.5 mm
When is the double bleb sign best seen?
Transvaginally between the 5th and 7th weeks gestation
One of the most emergent diagnoses made with sonography, is a pregnancy located outside of the central/fundal location of the uterus
Ectopic pregnancy
What percent of maternal deaths are related to ectopic pregnancy?
10%
Clinical findings of an ectopic pregnancy
Nonspecific pain, vaginal bleeding, positive pregnancy test, with an empty uterus, adnexal mass, pseudo sac(20% of patients), free fluid and a ring of fire appearance
Most common place for an ectopic pregnancy to occur.
Fallopian tube (95%)
Ectopic pregnancy that has increased risk of massive hemorrhage with rupture that may lead to hysterectomy or even death.
Interstitial portion of fallopian tube
Increased risk of complete hysterectomy because of uncontrollable bleeding
Cervical ectopic pregnancy
Maximum thickness of subcutaneous lucency at back of neck in embryo at 11 to 14 weeks gestation
Nuchal translucency
Nuchal translucency is increased in these patients.
Trisomy 13, 18 or 21 or fetuses with cardiac defects or other genetic syndromes
Age of a fetus when nuchal translucency can be performed
11 weeks and 13 weeks 6 days
Criteria for performing a nuchal translucency
CRL must be between 45-84 mm, 11-14 weeks gestation, embryo must be away from amniotic membrane with head in a neutral position,
Four chamber view of the heart can be seen as early as when?
12 weeks
Markers for cardiac defects
Increased nuchal translucency, tricuspid regurgitation, reversal or absence of flow in ductus venosus, ectopia cordis and limb body wall complex
When can the embryonic head be identified sonographically?
7 weeks
Partial or complete absence of cranium, a predecessor of anencephaly
Acrania
When does ossification of the cranium begin?
After 9 weeks
How early can acrania be reported?
12 weeks
What is the signcalled when a fetus has an abnormally shaped head?
Mickey mouse head
Congenital absence of the brain and cranial vault, cerebral hemispheres are either missing or reduced to small masses
Anencephaly
A midline cranial defect in which there is a herniation of the brain and meninges, may involve occipital, frontal, parietal, orbital, nasal or nasopharyngeal region of the head
Cephalocele
A rare, lethal anomaly of cranial development whose primary abnormalities include a defect in foramen magnum, retroflexion of spine and open spinal defects.
Iniencephaly
A dilation of ventricular system without enlargement of cranium, generally seen after 11 weeks
Ventriculomegaly
A malformation sequence that results from failure or prosencephalon to differentiate into cerebral hemispheres and lateral ventricles between 4th and 8th weeks
Holoprosencephaly
Holoprosencephaly three types
Alobar, semilobar, and lobar
Most serious form of holoprosencephaly, consists of a single ventricle, small cerebrum, fused thalami, agenesis of corpus cllosum, and falx cerebri
Alobar holoprosencephaly
Ventricles develop when?
after 9 weeks
Results from cystic dilation of fourth ventricle with dysgenesis or complete agenesis of cerebellar vermis and frequently hydrocephaly. Occurs around 6-7 weeks
Dandy-Walker malformation
Sonographic presentation of a dandy-walker malformation in the first trimester
Large posterior fossa cyst with contiuous fourth ventricle, absent cerebellum and dilated third and lateral ventricles
Occurs when there is a failure of neural tube to close after 6 weeks gestation
Spina bifida
Abdominal wall defects
Omphalocele, gastroschisis and limb-body wall complex
One of the most common abnormalities seen in the first trimester, has a high association with chromosomal abnormalities, appear on the posterior aspect of the featal neck and upper thorax
Cystic Hygroma
Most common mass seen in first trimester of pregnancy, secretes progesterone necessary to preserve embryo. Should measure <5 cm with no septations
Corpus luteum cyst
partial or complete absence of the cranium
acrania reported as early as 12 weeks predecessor to anencephaly
congenital absence of the brain and cranial vault with the cerebral hemispheres missing or reduced to small masses
anencephaly “frog face” seen at the end of the first trimester
gestational sac without an embryo
blighted ovum (anembryonic pregnancy)
during the first trimester, the bowel normally herniates outside the abdominal cavity between 8 and 12 weeks
bowel herniation
protrusion of the brain from the cranial cavity
cephalocele midline cranial defect herniation of brain tissue and/or meninges (brain membranes)
complete expulsion of all products of conception, including embryo and deciduas
complete abortion
a physiologic cyst that develops within the ovary after ovulation, secretes progesterone, and prevents menses if fertilization occurs; may persist until the 16th to 18th week of pregnancy
corpus luteum cyst
fluid-filled structure (often with septations) initially surrounding the neck; may extend upward to the head or laterally to the body
cystic hygroma one of the most common abnormalities seen in the 1st trimester most common: Turner’s Syndrome Trisomy 21, 18, and 13 If the hygroma resolves by week 18, the chromosomes are usually normal
a pregnancy that implants in a location other than the center of the uterus
ectopic pregnancy
congenital defective opening in the wall of the abdomen just to the right of the umbilical cord; bowel and other organs may protrude outside the abdomen from this opening
gastroschisis difficult to diagnose in the first trimester
condition in which trophoblastic tissue overtakes the pregnancy and propagates throughout the uterine cavity; partial and complete
gestational trophoblastic disease –
simultaneous intrauterine and extrauterine pregnancy
heterotopic pregnancy
failure of forebrain to divide into two cerebral hemispheres, resulting in a single large ventricle with varying amounts of cerebral cortex; has been known to occur with trisomies 13, 15, and 18
holoprosencephaly should divide into cerebral hemispheres and lateral ventricles between week 4 and 8 3 types: Alobar (most serious), lobar, semilobar
pregnancy loss with products of conception remaining in the uterus
incomplete spontaneous abortion
a rare neural tube defect in which the brain tissue protrudes through a fissure in the occiput, so that the brain and the spinal cord occupy a single cavity
iniencephaly occupital defect involving the foramen magnum retroflexed spine fetus looks upward open spinal defects are present
pregnancy occurring in the fallopian tube near the cornu of the uterus; also known as cornual pregnancy
interstitial pregnancy
congenital defect of the abdominal wall with protrusion of abdominal contents into the base of the umbilical cord; the cord appears to enter the mass
omphalocele difficult to diagnose in the first trimester
decidual reaction with fluid occurring within the uterus in a patient with an ectopic pregnancy
pseudogestational sac
additional term for missed abortion or miscarriage
spontaneous pregnancy loss (SPL)
a nonlethal genetic abnormality; chromosomal makeup is 45XO instead of the normal 46XX or 46XY. Cystic hygroma often is seen in affected fetuses in the first trimester. Survivors tend to be short in stature with low-set ears, webbing of the neck, a shield-shaped chest, and infertility as a result of an endocrine disorder caused by failure of the ovaries to respond to pituitary hormone
Turner’s syndrome
dilation of the cerebral ventricles without enlargement of the cranium
ventriculomegaly
results from a cystic dilation of the 4th ventricle with dysgenesis or complete agenesis of the cerebellar vermis and frequently hydrocephaly
Dandy Walker 6 to 7 week of gestation
spinal irregularities with bulging within the contour of the spine
spina bifida can be detected late 1st trimester
