Maternal and neonatal outcomes after oxytocin augmentation in patients undergoing a trial of labor after prior cesarean delivery

Abstract

Objective: To study the safety of oxytocin augmentation in patients having abnormal labors after a prior cesarean delivery.

Methods: We retrospectively analyzed a case series of women undergoing a trial of labor after a previous cesarean delivery from the University of California San Francisco perinatal data base. Women whose labors were augmented with oxytocin were compared to women with labor abnormalities managed without the use of oxytocin. A wide range of maternal and neonatal outcomes was compared. Only vertex singleton term deliveries were studied.

Results: From 1975-1990 there were 504 trials of labor, of which 185 (37%) had labor abnormalities; 62 of these 185 (34%) were augmented with oxytocin. Fifty-eight percent of the trials of labor ended in vaginal delivery. In patients since 1982, 73% delivered vaginally. Forty-six (74%) of augmented patients delivered vaginally. There were no maternal deaths, uterine ruptures, or hysterectomies. Estimated blood loss was slightly greater among augmented patients after controlling for mode of delivery (P < .05), but only by 50-100 mL on average. There was no difference in the need for maternal transfusion. Fetal trauma and fetal scalp blood sampling occurred more frequently (P < .05) in the augmented labors, but only in the subgroup delivered by cesarean. No increased risk was demonstrated by a comparison between patients receiving oxytocin and epidural anesthesia and patients with labor abnormalities receiving neither.

Conclusion: Retrospective analysis supports the use of oxytocin and epidural anesthesia to augment abnormal trials of labor after prior cesarean.