Comparison of induced labour pattern in women with premature rupture of membranes at term and those with intact membranes

Background: Membrane rupture may be integral to labour initiation in paturients with premature rupture of membranes [PROM] and therefore, it may be logical to expect that their labour characteristic and pattern should differ from those with intact membrane undergoing induction of labour. This study compared the ′a′bour characteristics in patients with PROM who had stimulation of uterine contractions with oxytocin with ′tose parturients with intact membranes who underwent induction of labour. Wtethod: This was a retrospective study conducted at the Obstetrics and Gynaecology department of the University of Benin Teaching Hospital (UBTH). The case files of 463 consecutive patients for induction/stimulation of labour from October 2008 to September 2009 were reviewed. Paturients were located into two groups; those with term premature rupture of membranes (PROM) and those with intact membranes who underwent induction of labour. Comparison was made between the labour characteristics of groups, mode of delivery, intrapartum complications and neonatal outcome. Results: During the study period a total of eligible 284 paturients with intact membranes had induction of labour [IOL], while 179 paturients with PROM had stimulation of labour [SOL]. Both groups were comparable in their sociodemographic and clinical characteristics. Majority of the PROM cases were contracting at admission [40.8% to 22.5%], also they had significantly shorter latent period [3.3hrs to 5hrs], required less use of higher oxytocin dose [3.9% to 7.4%] and had shorter labour duration (induction f c delivery interval: 6.7hrs to 9.1hrs). There was no difference in their mode of delivery or caesarean section rate. There were no significant differences in intrapartum complications and neonatal outcome measures. Conclusion: The finding of a significant shorter latent period, requirement for less oxytocin dose and overall shorter duration of stimulated labour cases with PROM compared to induction of labour for those with intact membranes suggest that PROM may be a means of labour initiation by some parturients and thus implies that these two groups of paturients are different obstetric entities and should therefore be treated as such in their labour management and research consideration