Background/Aims: Elective induction of labor is controversial and has been linked to adverse pregnancy outcomes including higher rates of cesarean delivery. Many institutions have implemented measures to limit this practice. Our aim was to describe recent trends in the prevalence of elective induction.
Methods: A trend analysis was performed using data from 7 health plans participating in the Medication Exposure in Pregnancy Risk Evaluation Program, which includes linked health plan and state birth certificate data. Participating health plans represented 6 states within 3 US regions and a range of health care delivery models. We included deliveries from 2001 to 2007 and required that women be enrolled for the last trimester of pregnancy or longer. Induction was identified from birth certificate and health plan data and was defined as elective if neither source revealed an accepted indication for induction (e.g. diabetes, preeclampsia, and others). We compared induction prevalence across sites and over time, both unadjusted and also adjusted for health plan, gestational age, maternal age, and parity. Adjusted rates were estimated by marginal standardization using logistic regression.
Results: These analyses include 524,730 deliveries. Induction for any indication occurred in 27% (19,582/73,553) in 2001, rising to 32% (23,366/73,958) in 2005 and then declining to 29% (22,561/77,063) in 2007. Elective induction occurred in 10% (7,152/73,553) in 2001, rising to 13% in 2005 (9,924/73,958) and 2006 (9,937/78,357) and then declining slightly to 12% (8,877/77,063) in 2007. The lowest prevalence for elective induction at any site in any year was 7% (2,029/27,107) and the highest, 18% (454/2,480). At only one site did the prevalence of elective induction increase every year of the study period: from 10% to 15% (p<0.01 for trend). Adjusted results were similar.
Conclusions: The prevalence of elective induction was highest in 2005-2006 and slightly lower in 2007. While there was considerable variation in prevalence across sites, elective induction continued to increase at only one site after 2005. Our data suggest that overall, in this setting, elective induction may have plateaued or even begun to decline.