[Epidural analgesia in latent phase of labor: effects on length of labor and mode of delivery].

Objective: To compare the outcome of ropivacaine plus sufentanil for patient-controlled epidural analgesia between nulliparous women presenting in latent and active labor.

Methods: 360 nulliparous parturients were randomized according to cervix dilation. Latent group (cervix dilation < 3 cm) received 0.1% ropivacaine with 0.5 microg/ml sufentanil and active group (cervix dilation > or = 3 cm) receive 0.15% ropivacaine with 0.5 microg/ml sufentanil, both followed by an infusion of 0.1% ropivacaine with 0.5 microg/ml sufentanil through PCEA. The PCEA pump was programmed to infuse a 6 ml bolus with a lockout interval of 15-20 min. The following were recorded: (1) pain intensity evaluated using VAS (0-10), (2) motor block assessed using modified Bromage scale, (3) onset of analgesia after epidural injection, (4) fetal heart rate, (5) maternal vital signs, (6) apgar score, (7) labor process, (8) mode of delivery and (9) the total amount of analgesic consumed.

Results: Both groups provided good analgesia. Early administration of epidural analgesia did not prolong the duration of first and second stage of labor. However, group L had a significant higher caesarean section rate and a significant lower instrumental delivery rate than group A. The reasons of cesarean section in both groups were arrested active phase and fetal distress. The reasons of instrumental delivery in both groups were fetal distress. The neonates had good outcome in both groups.

Conclusions: Compared with epidural analgesia in active phase of labor, early administration of epidural analgesia in latent phase did not prolong labor, however, the caesarean section rate was increased and instrumental delivery rate was decreased.