Obstetrics Flashcards
most common chromosomal anomaly associated with omphalocele
trisomy 18
omphalocele associated congenital anomalies
- cardiac 50%
- GU (bladder exstrophy, cloacal)
- CNS anomalies
pentalogy of Cantell
- omphalocele
- ectopia cordis
- congenital diaphragmatic hernia
- pericardial defect
- cardiac malformation
OEIS complex
- omphalocele
- bladder/cloacal exstrophy
- imperforate anus
- spinal anomalies
situs - stomach and cardiac apex on left
situs solitus
situs - stomach and cardiac apex on right
situs inversus
situs - stomach and cardiac apex opposing
left isomerism - polysplenia
right isomerism - asplenia
meckel gruber syndrome
- rare, lethal
- autosomal recessive
1. encephalocele
2. polycystic kidneys
3. polydactyly
placental infarct vs lake
infarct = thick echogenic rim lake = no rim
4 types of gestational trophoblastic neoplasia
invasive mole choriocarcinoma placental site trophoblastic tumour epithelioid trophoblastic tumour (dx made by FIGO criteria, no specific imaging findings to distinguish types of GTN)
theca lutein cyst definition
ovarian cysts related to hyperstimulation from elevated HCG in gestational trophoblastic disease
2 types of benign gestational trophoblastic disease
complete hydatidiform mole
partial hydatidiform mole
staging of gestational trophoblastic neoplasia
stage 1: confined to uterus
stage 2: extends outside uterus but limited to genital structures (adnexa, vagina, broad ligament)
stage 3: extends to lungs +/- genital tract involvement
stage 4: involves metastatic sites
choriocarcinoma definition & spread
malignant tumor arising from trophoblasts only (NO chorionic villi) +/- hemorrhage, necrosis
very aggressive (freq nuclear atypia, high mitotic activ)
50% follow molar preg, 25% follow abortion or tubal preg, 25% follow term, preterm preg
*hematogenous spread (cf. PSTT & ETT which spread to lymph nodes)
what are trophoblasts
- 1st cells to differentiate from fertilized ovum
- form outer layer of blastocyst
- eventually form FETAL PORTION of PLACENTA
- types: cyto-, syncytio-, intermediate trophoblasts
- “gestational trophoblastic disease”: group of disease characterized by abN prolif of trophoblasts
complete hydatidiform mole - pathophys
results from fertilization of an empty ovum by a sperm that then duplicates (90%) or by 2 sperm (10%)
- 46 XX or 46 XY
benign, MC form of GTD
beta HCG usually >100,000
partial hydatidiform mole - pathophys
usu results from fertilization of haploid ovum by 2 sperm
- 69 XXX or 69 XXY or 69 XYY
benign, less common than CHM
beta HCG elevated but usually <100,000
placental site and epithelioid trophoblastic tumors
rare forms of GTN
most often after term gestations
may present months to years after delivery
treated differently than invasive mole or choriocarcinoma
- hysterectomy + LN dissection +/- adj chemo (but relatively chemoresistant cf. choriocarcinoma)
marker up in omphalocele
AFP
normal AP renal pelvic diameter at:
- 16-27 weeks
- > 28 weeks
16-27 weeks: <4mm
> 28 weeks: <7mm
(postnatal: <10mm, measure after 48h of birth d/t dehydration)
readings suggestive of IUGR
- estimated fetal weight <10th percentile
- femur length/abdo circumference ratio >23.5
- umbilical artery systolic/diastolic ratio >4
causes asymmetric & symmetric IUGR
asymmetric: high BP, severe malnutr’n, ehler danlos
symmetric: TORCH, FAS, drug abus, chromosomal, anemia
normal separation of choroid plexus from medial wall lateral ventricle
<3 mm
larger = ventriculomegaly
normal cisterna magna size
2-11 mm
normal amniotic fluid index
5-20
<5 oligo
>20, or single pocket >8 poly
ddx echogenic bowel
cystic fibrosis downs trisomy 18 viral infections bowel atresia
timing of splitting for diamniotic vs monoamniotic
diamniotic = before 8 days monoamniotic = after 8 days
> 13 days can be conjoined twin
monochorionic complications
- twin twin transfusion
- twin anemia polycythemia sequence
- twin reversed arterial perfusion syndrome
- selective fetal growth restriction
- cord entanglement
- anomalies
- conjoined twins
- intrauterine fetal demise
gestational & yolk sacs tell us what for twins?
gestational sac = chorionicity
yolk sac = amnionicity
staging of twin twin transfusion syndrome
I - oligo-poly II - absent bladder in oligo baby III - doppler abN umbilical art +/- vien IV - fetal hydrops in 1+ V - fetal demise
diagnosis anemia and polycythemia in twins
Doppler USS MCA PSV
>1.5 multiples of median = anemia
<1.0 MoM = polycythemia
choroid plexus cyst ?normal ?aneuploidy
yes normal
yes associated with T18 & 21
turners associated with advanced maternal age?
no
complete/class mole vs partial mole
complete = 46 xx/xy, empty ovum 2 sperm partial = 69 xxy/xxx, ovum + 2 sperm
