[Induced labor: conditions for success and causes of failure. A prospective study of 162 cases]

The authors report the results of a prospective study of 162 cases of induced labour collected between 30 October 1990 and 31 December 1991 in the maternity unit of the Yaounde teaching hospital group. There were 1,640 deliveries during this period. Premature rupture of the membranes in 72 cases (44.4 per cent) and postmaturity in 42 cases (27.2 per cent) were the chief indications for the induction of labour in this study. There were 138 cases (85.2 per cent) of spontaneous delivery, 20 cases (12.3 per cent) of cesarean section and 4 cases (2.5 per cent) of vacuum extraction. Failure of induction occurred in 16 cases (9.8 per cent). Repeat induction of labour after a rest period led to spontaneous delivery in 6 cases. There were 6 fetal deaths, i.e. a perinatal mortality of 3.7 per cent. Postmaturity (3 cases) and premature rupture of the membranes (2 cases) were the risk factors in these six fetal deaths. Analysis of cases of failed induction and of fetal deaths in this study leads the authors to conclude that ripening of the cervix is an essential parameter for success of the artificial induction of labour. Premature rupture of the membranes, and postmaturity associated with an unripe cervix are unfavourable risk factors for the induction of labour and are potential indications for preventive cesarean section in order to avoid fetal death.