Mode of delivery after one caesarean section: audit of current practice in a health region

OBJECTIVE--To audit the subsequent obstetric management of women who had had one previous baby delivered by caesarean section. DESIGN--Retrospective analysis of a regional obstetric database. SETTING--Data derived from the 17 obstetric units in North West Thames region. SUBJECTS--1059 women who delivered a singleton fetus of at least 37 weeks9 gestation with a cephalic presentation in 1988 who had a history of one previous caesarean section and no other deliveries. MAIN OUTCOME MEASURES--Mode of delivery, postnatal morbidity, and duration of hospital stay. RESULTS--395 (37%) women were delivered by elective repeat caesarean section and 664 (63%) were allowed a trial of labour. Maternal height and birth weight of the previous infant differed significantly between those who were and those who were not allowed to labour. 471 (71%) of those allowed to labour achieved a vaginal delivery. In individual units there was no significant correlation between the proportion of patients allowed to labour and the rate of the successful trial of labour. There was a trend towards greater success rates in units that allowed a longer duration of labour (p less than 0.05) and units with greater use of oxytocin for augmentation of labour (not significant). Both elective and intrapartum caesarean section was associated with a significantly higher rate of postnatal infection than vaginal delivery (14.7% and 16.0% v 3.4%). CONCLUSIONS--In patients with a history of caesarean section there is no evidence that the likelihood of successful vaginal delivery after trial of labour is modified by the proportion of such patients allowed the option of attempted vaginal delivery. Until selection criteria of adequate prognostic value can be identified a more liberal approach to allowing women a trial of labour seems justified.