Obstetrics

Question 1

most common chromosomal anomaly associated with omphalocele

Answer 1

trisomy 18

Question 2

omphalocele associated congenital anomalies

Answer 2

• cardiac 50%
• GU (bladder exstrophy, cloacal)
• CNS anomalies

Question 3

pentalogy of Cantell

Answer 3

1. omphalocele
2. ectopia cordis
3. congenital diaphragmatic hernia
4. pericardial defect
5. cardiac malformation

Question 4

OEIS complex

Answer 4

1. omphalocele
2. bladder/cloacal exstrophy
3. imperforate anus
4. spinal anomalies

Question 5

situs - stomach and cardiac apex on left

Answer 5

situs solitus

Question 6

situs - stomach and cardiac apex on right

Answer 6

situs inversus

Question 7

situs - stomach and cardiac apex opposing

Answer 7

left isomerism - polysplenia

right isomerism - asplenia

Question 8

meckel gruber syndrome

Answer 8

• rare, lethal
• autosomal recessive
  1. encephalocele
  2. polycystic kidneys
  3. polydactyly

Question 9

placental infarct vs lake

Answer 9

infarct = thick echogenic rim
lake = no rim

Question 10

4 types of gestational trophoblastic neoplasia

Answer 10

invasive mole
choriocarcinoma
placental site trophoblastic tumour
epithelioid trophoblastic tumour
(dx made by FIGO criteria, no specific imaging findings to distinguish types of GTN)

Question 11

theca lutein cyst definition

Answer 11

ovarian cysts related to hyperstimulation from elevated HCG in gestational trophoblastic disease

Question 12

2 types of benign gestational trophoblastic disease

Answer 12

complete hydatidiform mole

partial hydatidiform mole

Question 13

staging of gestational trophoblastic neoplasia

Answer 13

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

Question 14

choriocarcinoma definition & spread

Answer 14

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)

Question 15

what are trophoblasts

Answer 15

• 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

Question 16

complete hydatidiform mole - pathophys

Answer 16

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

Question 17

partial hydatidiform mole - pathophys

Answer 17

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

Question 18

placental site and epithelioid trophoblastic tumors

Answer 18

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)

Question 19

marker up in omphalocele

Answer 19

AFP

Question 20

normal AP renal pelvic diameter at:

• 16-27 weeks
• > 28 weeks

Answer 20

16-27 weeks: <4mm

> 28 weeks: <7mm

(postnatal: <10mm, measure after 48h of birth d/t dehydration)

Question 21

readings suggestive of IUGR

Answer 21

1. estimated fetal weight <10th percentile
2. femur length/abdo circumference ratio >23.5
3. umbilical artery systolic/diastolic ratio >4

Question 22

causes asymmetric & symmetric IUGR

Answer 22

asymmetric: high BP, severe malnutr’n, ehler danlos
symmetric: TORCH, FAS, drug abus, chromosomal, anemia

Question 23

normal separation of choroid plexus from medial wall lateral ventricle

Answer 23

<3 mm

larger = ventriculomegaly

Question 24

normal cisterna magna size

Answer 24

2-11 mm

Question 25

normal amniotic fluid index

Answer 25

5-20 <5 oligo >20, or single pocket >8 poly

Question 26

ddx echogenic bowel

Answer 26

``` cystic fibrosis downs trisomy 18 viral infections bowel atresia ```

Question 27

timing of splitting for diamniotic vs monoamniotic

Answer 27

``` diamniotic = before 8 days monoamniotic = after 8 days ``` >13 days can be conjoined twin

Question 28

monochorionic complications

Answer 28

- twin twin transfusion - twin anemia polycythemia sequence - twin reversed arterial perfusion syndrome - selective fetal growth restriction - cord entanglement - anomalies - conjoined twins - intrauterine fetal demise

Question 29

gestational & yolk sacs tell us what for twins?

Answer 29

gestational sac = chorionicity | yolk sac = amnionicity

Question 30

staging of twin twin transfusion syndrome

Answer 30

``` I - oligo-poly II - absent bladder in oligo baby III - doppler abN umbilical art +/- vien IV - fetal hydrops in 1+ V - fetal demise ```

Question 31

diagnosis anemia and polycythemia in twins

Answer 31

Doppler USS MCA PSV >1.5 multiples of median = anemia <1.0 MoM = polycythemia

Question 32

choroid plexus cyst ?normal ?aneuploidy

Answer 32

yes normal | yes associated with T18 & 21

Question 33

turners associated with advanced maternal age?

Answer 33

no

Question 34

complete/class mole vs partial mole

Answer 34

``` complete = 46 xx/xy, empty ovum 2 sperm partial = 69 xxy/xxx, ovum + 2 sperm ```