Vaginal birth after one previous Caesarean section--evaluation of predictive factors.

Vaginal birth (or trial of labour) after previous Caesarean delivery represents one of the most significant changes in obstetric practice. A five-year retrospective study was carried out at the Lagos University Teaching Hospital to determine the obstetric outcome after a previous Caesarean section and also to identify significant clinical factors that are predictive of successful subsequent vaginal delivery. Hospital records of 101 patients with previous Caesarean births and 105 patients without a previous Caesarean delivery were examined, the later group serving as control. Successful vaginal delivery occurred in 74 (73.3%)) in the trial group and 90 (85.7%) in the control group. The Caesarean section rate was significantly higher in the trial group (P < 0.01). In the trial group, clinical factors found to predict successful vaginal delivery were a history of previous vaginal delivery (88.1%), infants birth weight less than 4kg (75%), gestational age less than 40 weeks (83.2%) and spontaneous onset of labour (82.1%). 63.6% of patients whose indications for previous Caesarean section were due to cephalo pelvic disproportion/ arrest of labour were successfully delivered vaginally. This indicates that each patient should be selected for appropriate management based on individual merits independent of past indication for caesarean section. Clinical factors found not to favour successful vaginal delivery were fetal macrosomia, post dates and induced labour. Uterine rupture/dehiscence occurred in 3 (2.97%) patients. No maternal or perinatal death occurred. We conclude from this study that trial of labour in carefully selected patients with previous Caesarean delivery poses low level of risk for both the mother and the baby and that its use is an important component of efforts to lower the rate of repeat Caesarean birth.