LAUSR

OBJECTIVE: Advanced maternal age pregnancies are commonly induced after 40 weeks. It is debatable whether term induction of labor (IOL) before 40 weeks gestation increases the risk of a cesarean delivery (CD). The purpose of this study was to evaluate the effect of a hospital’s liberal IOL approach prior to 40 weeks in term uncomplicated advanced maternal age pregnancies on CD rate. STUDY DESIGN: We conducted a retrospective population-based cohort study using the 2014 Health Care and Utilization Project Nationwide Inpatient Sample from the United States. We created a cohort of births taking place in hospitals with at least 200 deliveries and a CD of at least 5%. For our analysis, we included all births to women aged 40 years beyond 37 weeks, excluding pregnancies with indications for CD (malpresentation, multiple gestations, genital herpes and abnormal placentation). Hospitals were categorized as having a liberal IOL approach if the IOL rate was 20% or above. We used descriptive statistics to compare patient characteristics between the hospital groups and used logistic regression to estimate the adjusted effect of hospital IOL practice on CD rate in our target population. RESULTS: The study included 11,490 deliveries that took place in 1,221 hospitals. Of them, 618 hospitals (50.6%) were considered to have a liberal IOL practice of 20% and 603 hospitals did not (49.4%). The hospitals with high IOL rates were more likely to have Caucasian patients that belong to a higher income quartile. Hospitals with liberal IOL practices had lower CD rates than hospitals with a low IOL rate (22.2% vs 29.7% respectively, adjusted odds ratio1⁄40.73; 95% confidence interval 0.65-0.81, p<0.0001). CONCLUSION: Hospitals with a high IOL rate before 40 weeks have a lower CD rate in uncomplicated pregnancies of advanced maternal age. More liberal practices for IOL prior to 40 weeks may reduce cesarean delivery rates in these higher risk pregnancies.