Maternal and perinatal outcomes of induction of labor at term in the university clinics of Kinshasa, DR Congo

Abstract

Objective: This paper aims at assessing outcomes following induction of labor and characteristics likely to predict vaginal delivery. Study design: This is a descriptive retrospective cohort study including all women with singleton pregnancies who delivered at term in the university clinics of Kinshasa, DR Congo, from January 01, 2006 until December 31, 2010. Induction was initiated regardless of cervical status. Methods of induction included: oxytocin perfusion, vaginal Misoprostol, intracervical insertion of the Foley catheter and amniotomy. Results of induction were compared in terms of failure of labor, cesarean section, fetal distress, and neonatal distress. Logistic regression was used to seek for independent contributing factors for adverse outcomes. Results: During the period of the study 115 patients at term (3.2%) were concerned with induction of labor. Means for maternal age, gestational age and weight at confinement were 30.5 ± 5.7 years, 37.95 ± 1.54 weeks and 69.3 ± 15.1 kg, respectively. The mean parity and gravidity were 2.4 ± 1.9 and 2.9 ± 1.9, respectively. The mean Bishop score was 6.2 ± 1.5 at the first induction, with 66 women (57.3%) having less than 7. Indications for induction were: preeclampsia (52 = 54.1%), premature rupture of membranes (34 = 29.5%), post term (17 = 14.6%), gestational diabetes (5 = 4.3%), stillbirth (5 = 4.3%), polyhydramnios (3 = 2.6%) and cardiopathy (1 = 0.8%). Methods of induction at the first attempt included: oxytocin (86 = 74.7%), vaginal misoprostol (20 = 17.3%), transcervical Foley catheter balloon (14 = 12.1%), and amniotomy (1 = 0.8%). Failure to induce uterine contraction at the first attempt was noted in 9/115 (7.8%) women. Vaginal delivery occurred in 78 (66.9%) women, and cesarean section in 34 (29.6%). The majority of cesarean sections were performed at the primary induction, most of them (29/34 = 85.3%) in women with bad Bishop score. Failure of induction was more likely to occur in association with high maternal weight (OR 6.8; CI 1.2 - 39.7), and somewhat birth weight (OR 2.1 but CI containing 1). Risk for cesarean section was increased in association with induction of labor in cases of high maternal weight (OR 10.3, CI 16.0 - 67.0), and somewhat of high birth weight (OR 2.3, but CI containing 1). Fetal distress was associated only with maternal weight (OR 15.7, CI 1.3 - 187.8), and neonatal distress only with Bishop score (OR 10.9, CI 1.1 - 108.0). Conclusion Induction of labor in our setting in order to get vaginal delivery is affected of a high risk of adverse outcomes such as failure of induction, cesarean delivery, fetal and neonatal distress. This risk is significantly influenced by maternal weight, birth weight and Bishop score. Lack of worse outcomes between the first and the subsequent attempts to induce labor can be regarded as a reason to try induction even in the presence of unfavorable cervix.