,OB/GYN Essentials for USMLE Step 2 CK:
Fetal Surveillance, Hypertensive Disorders
& Clinical Case Logic (2025).
What are the antepartum fetal surveillance tests?
- Nonstress test
- Biophysical profile
- Contraction stress test
- Doppler sonography of the umbilical artery
What test involves external fetal heart rate monitoring for 20-40 minutes?
Nonstress test
What is a normal result for a nonstress test?
≥ 2 accelerations (reactive)
What is an abnormal result for a nonstress test?
- < 2 accelerations (nonreactive)
- Recurrent variable/late decelerations
What does the biophysical profile involve?
Nonstress test + U/S assessment of:
1. Amniotic fluid volume
2. Fetal breathing movement
3. Fetal movement
4. Fetal tone
How is each U/S parameter of the biophysical profile scored?
- Normal: 2 points per category
- Abnormal: 0 points per category
What is a normal result for a biophysical profile?
8 or 10 points
What is an abnormal result for a biophysical profile?
- Equivocal: 6 points
- Abnormal: 0, 2, or 4 points
- Oligohydramnios
, What test involves external fetal heart rate monitoring during spontaneous or induced uterine
contractions?
Contraction stress test
What is a normal result for a contraction stress test?
No late or recurrent variable decelerations
What is an abnormal result for a contraction stress test?
Late decelerations w/ >50% of contractions
What does a Doppler sonography of the umbilical artery involve?
Evaluation of flow in IUGR only
What is a normal result for Doppler sonography of the umbilical artery?
High-velocity diastolic flow in the umbilical artery
What is an abnormal result for Doppler sonography of the umbilical artery?
Decreased, absent, or reversed end-diastolic flow
What does a BPP score of 0-4 out of 10 indicate?
Fetal hypoxia due to placental dysfunction/insufficiency
What does a BPP score of 0-4 out of 10 necessitate?
Urgent delivery
What should be done for a BPP score of 6 out of 10?
Repeat BPP in 24 hours
What does a BPP score of 8-10 out of 10 indicate?
Well-oxygenated fetus
What is required in terms of antepartum surveillance for a pregnant patient diagnosed w/ gestational
hypertension?
Weekly BPPs starting at 32 weeks
What are the indications for magnesium sulfate administration?
- Seizure prophylaxis in preeclampsia w/ severe features
- Fertal neuroprotection at 24-32 weeks gestation when preterm birth is anticipated in the next 24 hours
ABO incompatibility generally occurs in whom?
Group O mother + Group A/B baby
What produces less severe hemolytic disease of the newborn: ABO or Rh(D) incompatibility?
Fetal Surveillance, Hypertensive Disorders
& Clinical Case Logic (2025).
What are the antepartum fetal surveillance tests?
- Nonstress test
- Biophysical profile
- Contraction stress test
- Doppler sonography of the umbilical artery
What test involves external fetal heart rate monitoring for 20-40 minutes?
Nonstress test
What is a normal result for a nonstress test?
≥ 2 accelerations (reactive)
What is an abnormal result for a nonstress test?
- < 2 accelerations (nonreactive)
- Recurrent variable/late decelerations
What does the biophysical profile involve?
Nonstress test + U/S assessment of:
1. Amniotic fluid volume
2. Fetal breathing movement
3. Fetal movement
4. Fetal tone
How is each U/S parameter of the biophysical profile scored?
- Normal: 2 points per category
- Abnormal: 0 points per category
What is a normal result for a biophysical profile?
8 or 10 points
What is an abnormal result for a biophysical profile?
- Equivocal: 6 points
- Abnormal: 0, 2, or 4 points
- Oligohydramnios
, What test involves external fetal heart rate monitoring during spontaneous or induced uterine
contractions?
Contraction stress test
What is a normal result for a contraction stress test?
No late or recurrent variable decelerations
What is an abnormal result for a contraction stress test?
Late decelerations w/ >50% of contractions
What does a Doppler sonography of the umbilical artery involve?
Evaluation of flow in IUGR only
What is a normal result for Doppler sonography of the umbilical artery?
High-velocity diastolic flow in the umbilical artery
What is an abnormal result for Doppler sonography of the umbilical artery?
Decreased, absent, or reversed end-diastolic flow
What does a BPP score of 0-4 out of 10 indicate?
Fetal hypoxia due to placental dysfunction/insufficiency
What does a BPP score of 0-4 out of 10 necessitate?
Urgent delivery
What should be done for a BPP score of 6 out of 10?
Repeat BPP in 24 hours
What does a BPP score of 8-10 out of 10 indicate?
Well-oxygenated fetus
What is required in terms of antepartum surveillance for a pregnant patient diagnosed w/ gestational
hypertension?
Weekly BPPs starting at 32 weeks
What are the indications for magnesium sulfate administration?
- Seizure prophylaxis in preeclampsia w/ severe features
- Fertal neuroprotection at 24-32 weeks gestation when preterm birth is anticipated in the next 24 hours
ABO incompatibility generally occurs in whom?
Group O mother + Group A/B baby
What produces less severe hemolytic disease of the newborn: ABO or Rh(D) incompatibility?
