Purpose: To evaluate whether induction of labor (IOL), as compared with expectant management, in gestational diabetes mellitus (GDM) mothers at term (between 370/7 and 406/7), decreases caesarean section (CS) rate and the rate of adverse composite neonatal outcomes.
Methods: A retrospective cohort study, of all women with GDM and a singleton gestation who delivered at term in a single, tertiary, university-affiliated medical center (2007-2014). We compared outcomes of women who underwent IOL at each week of gestation between 370/7 and 406/7 weeks with women who were managed expectantly. The primary outcome was CS rate.
Results: Overall, 2472 GDM patients included in the study, of which 880 women had IOL. CS rate was not found to be significantly different between the groups at any gestational age. IOL at 37 weeks was associated with adverse composite neonatal outcome (aOR 2.2, 95% CI 1.4-3.6) and NICU admission (aOR 2.5, 95% CI 1.4-4.4). At 38 weeks, with NICU admission (aOR 2.0, 95% CI 1.4-2.9), and at 39 weeks with fracture of the clavicle. In a sub-analysis of nulliparous women, IOL at 37 weeks had higher odds of NICU admission and adverse composite neonatal outcomes, at 38 weeks with CS and at 39 weeks with fracture of the clavicle.
Conclusions: IOL in GDM mothers at term does not reduce CS rate and may be associated with increased CS rate among nulliparous women at 38 weeks. It is also associated with increased risk for adverse composite neonatal outcome or NICU admission when done prior to 390/7 weeks.
Keywords: Cesarean section; Gestational diabetes; Induction of labor; Maternal outcome; Neonatal outcome.