165: Unintended effects of a statewide policy limiting elective early delivery: effects on high-risk pregnancies

Objective
In 2011, the Oregon Perinatal Collaborative implemented a hard-stop policy across Oregon hospitals to limit elective early-term deliveries (37-38 weeks’ gestation). The policy was not intended to affect obstetric practice for women with medical indications for early-term delivery. We tested for potential unintended effects of this policy among high-risk pregnancies. Specifically, we analyzed the impact of the policy on early-term inductions and adverse perinatal outcomes among women with hypertension and/or diabetes.
Study Design
This was a retrospective analysis of Oregon births to women with hypertension and/or diabetes before (2008-2010) and after (2012-2013) the implementation of Oregon’s hard-stop policy. The primary outcome was the rate of early-term inductions among high-risk women. We also examined the rates of adverse outcomes potentially resulting from changes in obstetric practice and prolonged gestation (e.g., stillbirth, chorioamnionitis, and perineal lacerations). We fitted logistic regression models for each outcome, controlling for potential confounders (maternal sociodemographic characteristics, BMI, parity, prenatal care utilization, and insurance coverage).
Results
Early-term inductions among high-risk pregnancies decreased following implementation of Oregon’s hard-stop policy, from 20.2% (pre-policy) to 16.8% (post-policy) (aOR = 0.82). The overall rate of term inductions did not significantly change; however, inductions at 39 weeks increased after policy implementation (32% to 34%; aOR = 1.12). When stratified by risk condition, rates of early-term induction decreased among women with gestational hypertension (28.7% to 23.7%; aOR = 0.77) and gestational diabetes (12.6% to 10.6%; aOR = 0.86), while no significant changes were observed for women with chronic hypertension and pre-pregnancy diabetes. Rates of adverse outcomes did not differ between pre- and post-policy periods, except for an increase of chorioamnionitis after policy implementation (1.8% to 3.2%; aOR = 1.88).
Conclusion
Oregon’s hard-stop policy likely affected obstetric practice for women not targeted by the policy. Reassuringly, most outcomes did not differ between pre- and post-policy periods. However, the potential for unintended changes in practice for high-risk women may be of concern and deserves further study.