In a pregnant woman with confirmed placental insufficiency, is induction of labor indicated and at what gestational age should it be performed?

Induction of Labor for Placental Insufficiency

Yes, induction of labor is indicated for placental insufficiency, with timing determined by the severity of Doppler abnormalities and degree of fetal growth restriction. 1

Delivery Timing Based on Severity of Placental Insufficiency

The gestational age at delivery depends critically on umbilical artery Doppler findings, which reflect the degree of placental dysfunction:

Normal Doppler with FGR

• Deliver at 38-39 weeks when estimated fetal weight is between 3rd-10th percentile 1
• Serial umbilical artery Doppler assessment every 2 weeks until delivery 1

Decreased Diastolic Flow

• Deliver at 37 weeks gestation when umbilical artery Doppler shows decreased (but not absent) diastolic flow 1, 2
• Weekly umbilical artery Doppler evaluation is required prior to delivery 1

Absent End-Diastolic Velocity (AEDV)

• Deliver at 33-34 weeks gestation because neonatal morbidity/mortality rates with AEDV exceed complications of prematurity at this gestational age 1, 2
• Doppler assessment 2-3 times per week is necessary 1
• At 37 weeks with AEDV, immediate delivery is required as the patient is already 3-4 weeks beyond the recommended delivery window 2

Reversed End-Diastolic Velocity (REDV)

• Deliver at 30-32 weeks gestation due to severe placental dysfunction with high risk of fetal demise 1
• Hospitalization with cardiotocography 1-2 times per day is required 1

Mode of Delivery Considerations

Cesarean delivery should be strongly considered for placental insufficiency with absent or reversed end-diastolic velocity 1, 2:

• FGR fetuses with abnormal Dopplers have 75-95% rates of intrapartum fetal heart rate decelerations requiring emergency cesarean delivery 1, 2
• These fetuses cannot tolerate the stress of labor contractions given severe placental dysfunction 2
• Induction of labor with an unfavorable cervix in FGR with abnormal Doppler carries a 38.4% cesarean rate, with abnormal Doppler being independently associated with 3.5-fold increased cesarean risk 3

Pre-Delivery Interventions

Antenatal corticosteroids should be administered if delivery is anticipated before 33 6/7 weeks or between 34 0/7 and 36 6/7 weeks in women at risk of delivery within 7 days 1

Magnesium sulfate should be administered for fetal neuroprotection for pregnancies <32 weeks gestation 1

Coordinate with neonatology for optimal resuscitation planning, as these infants are at high risk for respiratory distress syndrome, necrotizing enterocolitis, and intraventricular hemorrhage 2

Critical Pitfalls to Avoid

• Do not attempt labor induction when absent or reversed end-diastolic flow is present at term, as the fetus cannot tolerate the stress of contractions 1, 2
• Do not continue expectant management beyond the recommended delivery windows based on Doppler findings, as this markedly increases the risk of stillbirth 2
• Do not rely solely on biophysical profile or cardiotocography for surveillance; umbilical artery Doppler is the primary surveillance tool 1
• Do not use ductus venosus, middle cerebral artery, or uterine artery Doppler for routine clinical management of FGR 1

Post-Delivery Assessment

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