Predictors for successful induction of labour at Muhimbili National Hospital

Research Article

Abstract

Induction of labor is the use of techniques for stimulating uterine contractions to accomplish vaginal delivery prior to the onset of spontaneous labor. Induction of labor with the goal of achieving vaginal delivery prior to spontaneous onset of labor is recommended when the benefits of delivery out-weight the risk of continuing the pregnancy.

The practice of induction of labor at Muhimbili National Hospital is faced with low success rate of about 60% compared to more than 80% success in the developed world. The low success rate of IOL at MNH could be contributed by factors beyond the known predictors for induction success. The study intended to identify the predictors for successful induction of labour at Muhimbili National Hospital.

Methodology: Analytical cross-sectional study on women undergoing induction of labor at MNH. These were women with indication for IOL, single viable fetus with cephalic presentation, gestational age of ≥ 28 weeks, recruited consecutively before IOL until sample size was reached. Social demographic, obstetric characteristics were obtained through patient interview and methods of inductions, time of initiation of first dose were obtained from the patients files, all these were collected using a structured questioner, then analysed using SPSS version 23 computer program.

Univariate analysis was used to describe socio-demographic characteristics, while Bivariate and multivariate were used to determine the association of factors with success of induction of labor. P value <0.05 was considered statistically significant in all tests of significance.

Results; The study included 400 women, of these participants, 297(74.2%) had success of vaginal delivery while 103(25.8%) had failure of IOL. The hypertensive disorders were the commonest indications of IOL 182(45.5%) followed by post-date 103(25.7%). Methods of IOL, number of doses of prostaglandins used, parity (AOR 1.8; 95%CI= 1.1,1.3), favorable cervix (AOR=5, 95% CI=1.8,13.6), term (AOR=2;95% CI=1.3,3.7) and postterm pregnancy (AOR=2.8; (95% CI=1.5,5.4) were independently associated with success of IOL. Other characteristics such as maternal age and fetal weight were not associated with success of IOL.

Conclusion: The main predictors of the outcome of IOL were Bishop score greater than 7, term and postterm, use of amniotomy with oxytocin, misoprostol and parity greater than one. IOL carries high risk of maternal morbidity, it is mandatory to assess predictors for success of before IOL.