Perinatal and maternal outcomes of high dose versus low dose oxytocin regimen for labor induction in four hospitals of Ethiopia

Abstract

Background: Induction of labor is routine obstetric procedure. Oxytocin for the purposes of induction of labor is one of the most frequently used medications in obstetrics. Studies have estimated the relative efficacy and safety of high-dose versus low-dose oxytocin protocols for induction of labor. However, little is known regarding the optimal dose of oxytocin and maternal and perinatal outcomes. Objective: To compare perinatal and maternal outcomes of high-dose compared with low-dose oxytocin regimen for labor induction among mothers who will give birth in four selected hospitals of Ethiopia. Methodology: Facility based a comparative cross-sectional study design was used. The study was conducted in four selected Ethiopian hospitals. All pregnant women who undergo induction of labor at GA of > 37 weeks in all the four selected facilities were included starting from October 1, 2017 till May 30, 2018. Code was given to questionnaire collected by face-to-face interview by structured questionnaire. Data was entered into Epidata version 3.1 and then exported to SPSS version 20 for cleaning and analysis. To explain the relationship of relevant variable; cross-tabulation between dependent and independent variables was conducted and simple relationship was checked. Bivariate and multivariate logistic regression was done to look for predictors of successful induction, factors associated with adverse maternal outcome and adverse neonatal outcome. The result is presented using 95% confidence interval (CI) of odds ratios (OR). P-value < 0.05 was used to declare statistical significance. Result: A total of 216 laboring mothers are participated in the study in four hospitals. Overall mean age and gestational age at delivery for all participants were 26 years and 39.4 weeks respectively. Overall mean “oxytocin to delivery” time for study subjects is 5.9 hours and 6.3 hours for subjects of high dose group (HDG) and low dose group (LDG) respectively. Mean oxytocin concentration required till delivery is 77.6 mu/min and 22 mu/min for HDG and LDG respectively. Higher successful induction (72.2% versus 61.1%) and lower C/S rate (27.8% vs. 38.9) was observed among LDG as compared to HDG. Favourable bishop score [AOR=4.0, 95%CI: (1.9, 8.5 )], elective induction[AOR=0.2,95%CI: (0.1,0.4)] , performing ARM [AOR=10.1,95%CI:(3.2, 32.2 )], neonatal birth weight (NBW) of < 4Kg [AOR= 4.3, 95%CI: (1.6, 11.6)] and being parous [AOR=2.1, 95%CI: (1.1,4.0)] were found to be significantly associated with success of induction at P-Value < 0.05. While misoprostol use [AOR= 4.7, 95%CI: (1.6, 13.4) ] and NBW >4 kg[AOR= 3.4, 95%CI: (1.1, 10.3)] are associated with adverse maternal outcome, Oxytocin regimen [AOR=2.4, 95%CI: 1.1, 5.5], caesarean delivery [AOR=9.3, 95% CI: 3.8, 22.5], instrumental delivery [AOR=7.7, 95% CI: 2.1, 27.8], APH as indication for induction [AOR=17.8,95% CI: (1.9,168.7)] are found to be associated with adverse neonatal outcome at P-value < 0.05. Conclusion and recommendation: In the study high dose oxytocin regimen is significantly associated increased adverse perinatal outcome, slightly shorter oxytocin to delivery time, shorter duration of hospital stay. Favourable bishop score, emergent type of induction, performing ARM and delivery to neonate weighing < 4kg are positive predictors of successful induction. High dose oxytocin regimen, APH as indication of induction, caesarean delivery, and instrumental delivery are significantly associated with increased odds of adverse perinatal outcome while only misoprostol use and delivery to macrosomic neonate are associated with increased odds of adverse maternal outcome. The finding of the study favors the recommendation of low oxytocin regimen although more strong research that controls confounders is needed to come up with strong recommendation.