The effect of maternal position on fetal heart rate during epidural or intrathecal labor analgesia

OBJECTIVE: This study was designed to determine the relationship between maternal position and the incidence of prolonged decelerations after epidural bupivacaine or intrathecal sufentanil analgesia for labor. STUDY DESIGN: Laboring, healthy, term parturient women, with reassuring fetal heart rate tracings, requesting either epidural (n = 145) or intrathecal (n = 160) analgesia were randomly assigned to lie either supine with measured 30-degree left uterine displacement (n = 136) or in the left lateral decubitus position (n = 145). Patients received either intrathecal sufentanil, 10 mu g, or epidural 0.25% bupivacaine, 13 mL. An obstetrician, unaware of patient position or type of anesthesia, examined the fetal heart rate tracings. RESULTS: No demographic differences were noted among the groups. Prolonged decelerations occurred with equal frequency after epidural bupivacaine and intrathecal sufentanil (3.9%). Prolonged decelerations were not related to maternal position. No emergency cesarean deliveries were performed as a result of prolonged decelerations. Prolonged decelerations correlated with the frequency of contractions before induction of analgesia (P<.05). Fewer fetal heart rate accelerations were noted after intrathecal sufentanil than after epidural bupivacaine (P<.005). More ephedrine was used after epidural bupivacaine (P<.001). Patients who received epidural analgesia in the left lateral position were more likely to have an asymmetric block (P<.05). CONCLUSIONS: The risk of prolonged deceleration after epidural bupivacaine or intrathecal sufentanil labor analgesia is unrelated to maternal position or analgesic technique.