What is the appropriate next step in management for a pregnant patient at 37 weeks of gestation with a fundal height corresponding to 35 weeks and absent end-diastolic flow on umbilical artery Doppler (Umbilical Artery Doppler Ultrasound)?

Immediate Delivery by Caesarean Section (Option B)

At 37 weeks gestation with absent end-diastolic flow (AEDF) on umbilical artery Doppler, immediate delivery by caesarean section is the appropriate next step in management.

Rationale for Immediate Cesarean Delivery

AEDF at 37 weeks represents a critical situation where the fetus has already exceeded the recommended delivery window of 33-34 weeks, making immediate delivery mandatory rather than expectant management. 1, 2

• AEDF indicates severe placental insufficiency with obliteration of approximately 70% of placental tertiary villi arteries, creating a high-risk situation that mandates delivery 1
• The Society for Maternal-Fetal Medicine recommends delivery at 33-34 weeks of gestation for pregnancies with fetal growth restriction and AEDF 3, 2
• Delaying delivery beyond 34 weeks in cases of AEDF significantly increases the risk of adverse outcomes 2
• Perinatal death occurs in >20% of pregnancies with AEDF, with significantly worse outcomes when vaginal delivery is attempted 1

Why Cesarean Section Over Induction

Labor induction should never be attempted with AEDF, as the fetus cannot tolerate the stress of contractions given the severe placental insufficiency. 1

• AEDF is the most predictive Doppler finding for adverse perinatal outcomes, outperforming other antenatal tests like NST and biophysical profile 1
• National guidelines from multiple countries recommend cesarean delivery when fetal growth restriction is complicated by AEDF 3
• Growth-restricted fetuses with AEDF are at increased risk for intrapartum fetal heart rate decelerations requiring emergency cesarean delivery and metabolic acidemia at delivery 3

Why Not Repeat Doppler in 1 Week

At 37 weeks gestation, this fetus is already 3-4 weeks past the recommended delivery window for AEDF (33-34 weeks), making further surveillance inappropriate. 3, 2

• Intensive surveillance protocols (daily cardiotocography, twice-weekly Doppler) are only appropriate for AEDF diagnosed before 34 weeks gestation 2
• The clinical scenario demands rapid delivery given the advanced gestational age combined with severe fetal compromise 4

Critical Clinical Pitfalls to Avoid

• Never attempt labor induction or augmentation with AEDF - the fetus cannot tolerate the stress of contractions 1
• Do not delay delivery beyond 34 weeks in AEDF cases, as this significantly increases adverse outcomes 2
• Distinguish AEDF from reversed end-diastolic flow (REDF), which is even more severe and requires earlier delivery at 30-32 weeks 3, 2
• Avoid managing AEDF without specialist consultation, as these cases require experienced obstetric or maternal-fetal medicine involvement 1

Pre-Delivery Management

• Obtain cord arterial and venous pH at delivery to assess the degree of fetal compromise 1
• Send the placenta for histopathologic examination to guide future pregnancy management 1, 2