Decision to delivery intervals for assisted vaginal vertex delivery.

OBJECTIVE: To describe the time interval between decision for assisted vaginal delivery and the birth of the baby in different clinical circumstances.

DESIGN: A prospective analysis of 225 consecutive women with a singleton fetal cephalic presentation in the second stage of labour requiring an operative vaginal delivery for various reasons.

SETTING: A maternity unit in a district general hospital delivering more than 6,000 women annually.

MAIN OUTCOME MEASURES: The decision to delivery interval and the immediate and short term maternal and neonatal outcomes according to indication for operative vaginal delivery.

RESULTS: The mean (SD) decision to delivery interval was 34.4 minutes (28.3) with a range of 5 to 101 minutes. For those delivered because of suspected fetal distress, the interval of 26.5 minutes (14.0) was significantly shorter than for those performed without fetal distress 39.5 minutes (19.0) (P < 0.0001); for cases with fetal distress, forceps were significantly quicker at 23.3 minutes (14.3) than the ventouse 29.2 minutes (13.2) (P = 0.04). The longer the interval in cases of fetal distress the less favourable the condition of the neonate at birth, although this trend did not reach statistical significance and was not seen for deliveries expedited for other reasons. Perineal repair was required following 96% forceps deliveries compared with 87% ventouse (P = 0.015). Perineal trauma was not influenced by the interval between decision and delivery.

CONCLUSIONS: If speed of delivery is important, use of forceps results in a quicker birth than use of the ventouse, without any compromise to the condition of the baby at delivery, and with similar rates of perineal trauma.