Induction of labour – a misused blessing: Prospective study of factors influencing the success of induction and comparison of fetomaternal outcomes with spontaneous labour

Abstract

Background. Although most pregnant women experience spontaneous labour at term, induction of labour is indicated whenever continuation of pregnancy is detrimental to either the fetus or the mother. 

Objectives. To study the factors associated with the successful induction of labour and to compare the maternal and fetal outcomes between induced and spontaneous labour. 

Methods. We conducted a prospective observational and comparative study from September 2015 to December 2016 at Dr TMA Pai Hospital – a secondary level hospital at Manipal Academy of Higher Education (MAHE). Women with a singleton pregnancy, live fetus, vertex presentation and gestational age (GA) >36 weeks were included in the study, and those with antepartum haemorrhage, scarred uterus, anomalous fetus and intrauterine fetal demise were excluded. 

Results. Out of 1 575 deliveries during the study period, 550 were induced (34%). A total of 300 inductions fulfilled the inclusion criteria and formed the study group. Multiparity, body mass index (BMI) <25 and gestational age (GA) >38 weeks were factors associated with successful induction. Among the components of the Bishop score, dilatation was a better predictor of vaginal delivery (p<0.001) and post-dated pregnancy was the most common indication (33.6%). The rates of caesarean section (CS) delivery (33% v. 12%) and neonatal intensive care unit (NICU) admissions (4% v. 1%) were more in the induced group compared with the spontaneous group. 

Conclusion. Multiparity, BMI <25 and advancing GA are predictors of successful induction. Induction is safe but carries a high risk of CS delivery and NICU admissions.