Efficacy and safety of misoprostol in induction of labour in a Nigerian Tertiary Hospital

Abstract

Background: Misoprostol - a stable prostaglandin E1 analogue- is effective and safe in the induction of labour. There is paucity of information about the use of misoprostol for labour induction in Nigeria. Objective: To evaluate the efficacy of misoprostol in the induction of labour in the third trimester. Methods: Consecutive patients for induction of labour were randomized into misoprostol or oxytocin study groups. The misoprostol group received intravaginal 50μg 6- hourly to a maximum of four doses. Those in the oxytocin group received a maximum of 48 iu/min. Outcome measures included induction-delivery interval, mode of delivery, Apgar score, perinatal death and maternal complications. Results: Sixty-two patients were recruited into the study-34 received misoprostol while 28 received oxytocin. The modal gestational age and Bishop score prior at induction were >36 weeks and 5-7 respectively. Hypertension in pregnancy was the commonest indication for induction of labour followed by prolonged pregnancy. The overall induction-delivery interval was 12.2 ± 5.2 hours; Misoprostol v oxytocin, mean(range): 12.1(7-27) vs 12.3(4-27) hours, p = 0.88). There were no significant differences in the mean Apgar score and perinatal mortality rate in the two study groups. There were two cases of primary postpartum haemorrhage in the oxytocin group but none in the misoprostol group. One case of ruptured uterus was encountered in the misoprostol group. No case of maternal mortality was recorded. Four patients in the misoprostol group had minor side effects mainly nausea and vomiting. Conclusion: The efficacy of misoprostol in the induction of third trimester labour is comparable to oxytocin. The risk of ruptured uterus associated with misoprostol appears higher than that of oxytocin in the induction of labour. Further studies are needed to verify this observation in our setting.