Obstetrics

Question 1

Quad screen markers in Down syndrome?

Trisomy 18?

Answer 1

Down: AFP and estriol down, HCG and inhibin up
T18: AFP, estriol, and HCG low, inhibin normal.

Question 2

Sinusoidal fetal heart rate tracing

Answer 2

Severe fetal anemia

Question 3

Treatment for short cervix with no history of premature delivery?
With history of premature delivery?

Answer 3

No Hx: intravaginal progesterone (tones down uterus)

Hx: Cerclage + intravenous progesterone (all women with hx of premature delivery get IV progesterone).

Question 4

Thyroid axis changes in pregnancy

Answer 4

Decreased TSH (cross-stimulation by HCG), increased total T4 (HCG), increased TBG (estrogen), normal (or slightly increased) free T4.

Question 5

Treatment for preterm labor

Answer 5

> =34 weeks: let labor proceed
<34 weeks: Tocolytics (nifedipine, indomethacin), betamethasone, penicillin if GBS positive/unknown.
<32 weeks: add mag for fetal neuroprotection.

Question 6

When is CVS possible? Amniocentesis?

Answer 6

CVS: 10-13 weeks
Amniocentesis: 15-20 weeks

Question 7

Baby with microcephaly, cleft palate, and hypoplasia of midface, digits and nails.

Answer 7

Phenytoin (fetal hydantoin syndrome)

Small size, hirsutism, and rib abnormalities also seen

Question 8

24-hour urine protein required to diagnosis preeclampsia?

Urine protein/creatinine ratio?

Answer 8

24-hour urine protein: >300 mg

P/C ratio: >0.3

Question 9

Define arrest in active phase of first stage of labor

Answer 9

4 hours of no cervical change with adequate contractions (200 MVU), or 6 hours with inadequate contractions
(Get a c-section)

Question 10

Define arrest in second stage of labor.

Most common cause?

Answer 10

No descent in 3 hours in a nulliparous woman, 2 hours in a multiparous
Most common cause: fetal malpositioning (others are cephalopelvic disproportion, inadequate contractions, maternal exhaustion).

Question 11

Most common neurological deficit associated with shoulder dystocia? What is injured? What does it look like?

Answer 11

Erb-Duchenne palsy due to C5/C6 lesion. “Waiter’s tip” and decreased moro with normal hand grip.

(Klumpke’s palsy less common: C8/T1, claw hand, hand paralysis, possibly Horner syndrome)
(Brachial plexus injury can be seen if clavicle or humerus is fractured)

Question 12

Uterotonics for postpartum hemorrhage. What is first line? What can you add if that fails? What, if any, are CI to each?

Answer 12

First-line: oxytocin
Second-line:
Methylergonovine: CI in HTN (vasoconstricts)
Carboprost: CI in asthma (bronchoconstriction)
Misoprostol: No CI, but can cause fever

Question 13

Antibiotics for postpartum endometritis

Answer 13

Clindamycin/gentamicin (infection usually polymicrobial)