Early versus late initiation of epidural analgesia in labor: does it increase the risk of cesarean section? A randomized trial.

OBJECTIVE: To determine whether early initiation of epidural analgesia in nulliparous women affects the rate of cesarean sections and other obstetric outcome measures.

STUDY DESIGN: A randomized trial in which 449 at term nulliparous women in early labor, at less than 3 cm of cervical dilatation, were assigned to either immediate initiation of epidural analgesia at first request (221 women), or delay of epidural until the cervix dilated to at least 4 cm (228 women).

RESULTS: At initiation of the epidural the mean cervical dilatation was 2.4 cm in the early epidural group and 4.6 cm in the late group (P < 0.0001). The rates of cesarean section were not significantly different between the groups--13% and 11% in the early and late groups, respectively (P = 0.77). The mean duration from randomization to full dilatation was significantly shorter in the early compared to the late epidural group--5.9 hours and 6.6 hours respectively (P = 0.04). When questioned after delivery regarding their next labor, the women indicated a preference for early epidural.

CONCLUSION: Initiation of epidural analgesia in early labor, following the first request for epidural, did not result in increased cesarean deliveries, instrumental vaginal deliveries, and other adverse effects; furthermore, it was associated with shorter duration of the first stage of labor and was clearly preferred by the women.