Background: Induction of labour is an important intervention in obstetrics. Misoprostol is increasingly being used for induction of labour in many obstetric units and it may replace the traditional Foleys catheter/oxytocin protocol.
Method: This was a retrospective study of the 3 methods of induction of labour used at the University of Maiduguri Teaching Hospital (UMTH). A total of 468 women had induction of labour during the study period. Two hundred and twenty eight of them had induction with 50 microg of misoprostol, 57 women had 100 microg of misoprostol while 183 women had extra-amniotic Foleys catheter with oxytocin infusion.
Result: Induction of labour constituted 6.6% (468/7086) of all deliveries during the study period. The commonest indication for induction of labour was prolonged pregnancy in 46.8%, followed by pregnancy induced hypertension in 33.5%. There was no difference in the achievement of vaginal delivery between the 3 methods of induction of labour (chi2 = 1.13, p = 0.57). The mean induction delivery time was shortest for those induced with 100 microg of misoprostol (6.38 +/- 2.25 hours), followed by 8.16 +/- 3.58 hours in those induced with 50 ug of misoprostol and 9.73 +/- 4.32. 43 hours in those induced with Foleys catheter/oxytocin (p < 0.001). The babies delivered to women induced with 100 microg of misoprostol were more asphyxiated 12.3% (7/57) compared to 9.2% (21/228) and 6.6% (12/183) in the 50 ug misoprostol and Foleys catheter/oxytocin respectively and was statistically significant (chi2 = 23.08, p = 0.01). The short induction delivery time in the group with 100 microg of misoprostol was advantageous but there was an associated higher risk of birth asphyxia, stillbirth, uterine hyperstimulation, perineal tear and uterine rupture. The normal delivery outcome was not significantly different from those induced with 50 microg of misoprostol and those induced with Foleys catheter/oxytocin (chi2 = 1.24, p = 0.94). Normal delivery rate was significantly higher in those induced with 50 microg of misoprostol compared with those induced with 100 microg of misoprostol (chi2 = 14.38, p = 0.01).
Conclusion: Misoprostol appears to be safe and may be a suitable alternative for induction of labour by the traditional Foleys catheter/oxytocin protocol. The 50 microg dosing of misoprostol is safer than the 100 microg.