The effect of ephedrine on intrapartum fetal heart rate after epidural analgesia.

OBJECTIVE: Adverse fetal heart rate (FHR) changes occur frequently during the first 30 minutes after epidural analgesia. The aim of this study was to estimate whether intravenous administration of ephedrine during induction of epidural analgesia can reduce the frequency of adverse FHR changes.

METHODS: We prospectively studied 145 term singleton deliveries where epidural analgesia was administered. The patients were randomly allocated before the administration of epidural analgesia to receive an intravenous infusion of 10 mg ephedrine, after epidural induction, followed by a continuous infusion for 60 minutes of 20 mg ephedrine (study group) or to receive no ephedrine (control group). The FHR tracing was evaluated for 20 minutes before and 40 minutes after initiating epidural analgesia. Demographic data and clinical and delivery outcome were assessed and compared between the 2 groups.

RESULTS: Injection of ephedrine significantly reduced the rate of major FHR changes appearing 15-25 minutes after induction of epidural analgesia in the study group compared with the control group (2/72 compared with 11/73, respectively; P = .009). To avoid 1 case of adverse FHR changes, 6.8 women should be treated with ephedrine. Maternal and fetal characteristics and outcome and mode of delivery were similar in the 2 groups. Mean arterial pressure was significantly higher in the study group from the time of analgesia induction and during the subsequent 25 minutes. Maternal heart rate was transiently reduced in the study group only.

CONCLUSION: Ephedrine administration during the time of epidural analgesia initiation can reduce the frequency of adverse FHR changes commonly observed immediately afterward.