Active pushing versus passive fetal descent in the second stage of labor: a randomized controlled trial.

OBJECTIVE: To compare perinatal outcomes among women with epidural anesthesia who were encouraged to push at complete dilatation with those who had a period of rest before pushing began.

METHODS: After a power analysis to determine appropriate sample size (based upon an alpha error rate of.05% and 80% power), a prospective randomized trial of 252 women with epidural anesthesia was conducted. Patients were randomized to a rest period or immediate pushing at complete dilatation. Variables measured included rate of fetal descent, length of time of pushing, the number and type of fetal heart rate decelerations, Apgar scores, arterial cord pH values, perineal injuries, type of delivery, length of second stage, maternal fatigue, and endometritis.

RESULTS: When a period of rest was used before pushing, we found a longer second stage, decreased pushing time, fewer decelerations, and, in primiparous women, less fatigue compared with control patients. Apgar scores, arterial cord pH values, rates of perineal injury, instrument delivery, and endometritis were similar in both groups.

CONCLUSION: Delayed pushing was not associated with demonstrable adverse outcome, despite second-stage length of up to 4.9 hours. In select patients, such delay may be of benefit.