Prospect for vaginal delivery of growth restricted fetuses with abnormal umbilical artery blood flow.

BACKGROUND The best mode of delivery in cases of intrauterine growth restriction (IUGR) with umbilical artery blood flow changes is not well elucidated. OBJECTIVE To evaluate outcome in IUGR with umbilical artery blood flow changes planned for vaginal delivery after a negative oxytocin challenge test (OCT). METHODS In 84 term singleton pregnancies with suspected IUGR and no unanimous indication for abdominal delivery, Doppler velocimetry and OCT were performed. Positive OCT cases were delivered by cesarean section, negative OCT cases planned for vaginal delivery. RESULTS Umbilical artery Doppler velocimetry was normal in 51 cases (normal group) and abnormal in 33 cases (increased pulsatility index with maintained forward diastolic flow). Gestational age at delivery was shorter (p = 0.008), positive OCT more common (33% vs. 16%; p = 0.06), and vaginal delivery less common (40% vs. 63%; p = 0.04) in the abnormal blood flow group compared with the normal flow group. When in labor, 68% in the abnormal flow group and 76% in the normal flow group delivered vaginally (p = 0.6). One baby had a lethal malformation and another suffered meconium aspiration and pneumothorax, but was discharged home healthy. CONCLUSIONS The vaginal delivery rate was significantly lower in the abnormal flow group compared with the normal flow group, but in cases finally destined for a trial of labor the vaginal delivery rates were similar. There was no indication that any fetus was exposed to detrimental hypoxia or distress.