Late Decelerations in a Growth-Restricted Fetus at 37 Weeks
A 27-year-old G1P0 at 37 weeks 1 day with diet-controlled gestational diabetes and a fetus with estimated fetal weight at the 6th percentile presents for a routine visit. The fetal heart rate tracing shows a baseline of 145, moderate variability, and recurrent late decelerations that resolve with maternal repositioning but recur within 10 minutes. The patient has a Bishop score of 4. Umbilical artery Doppler from 2 days ago showed a pulsatility index >95th percentile with positive end-diastolic flow. Amniotic fluid index is 6 cm. She is contracting irregularly. She asks whether she can go home and come back for induction next week.
1. How do you interpret the tracing and Doppler findings, and what is the immediate plan?
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Recurrent late decelerations with moderate variability suggest uteroplacental insufficiency, especially in a growth-restricted fetus with elevated umbilical artery pulsatility index. Positive end-diastolic flow indicates the fetus is not yet at the most severe stage, but recurrent late decelerations are abnormal and warrant intervention. The patient should not go home. Immediate steps: continuous fetal monitoring, maternal left lateral positioning, IV fluids, and consideration of tocolysis if contractions are contributing. If late decelerations persist, delivery is indicated. At 37 weeks, the fetus is term and delivery is appropriate. The judgment is that recurrent late decelerations in a growth-restricted fetus at term are an indication for delivery, not expectant management.
2. What mode of delivery would you recommend and why?
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The choice depends on the fetal status and the likelihood of a successful vaginal delivery. With a Bishop score of 4, the cervix is unfavorable, and induction may be prolonged. Given recurrent late decelerations, a cesarean delivery may be safer because it avoids the stress of labor and allows immediate delivery. However, if the tracing stabilizes and the fetus is reactive, induction with continuous monitoring is an option. The judgment is to weigh the risk of ongoing uteroplacental insufficiency against the risks of cesarean. In a growth-restricted fetus with recurrent late decelerations at term, cesarean is often preferred, especially if the tracing does not improve with intrauterine resuscitation. The patient should be counseled about the risks and benefits of both approaches.
3. What postpartum and neonatal considerations are important?
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The neonate is growth-restricted and may have hypoglycemia, hypothermia, and polycythemia; check glucose and hematocrit. Placental pathology may reveal infarction or maternal vascular malperfusion, which has implications for future pregnancies. The mother should be counseled about recurrence of growth restriction and preeclampsia, and about long-term cardiovascular risk. If cesarean, discuss thromboprophylaxis and wound care. The judgment is that delivery is not the end of care; the neonate and placenta require evaluation, and future pregnancy planning should include aspirin prophylaxis and early growth scans.