Impact of Medicaid Expansion on Interpregnancy Interval

Objectives: Medicaid expansion under the Affordable Care Act (ACA) improved access to reproductive health care for low-income women and birthing people who were previously ineligible for Medicaid. We aimed to evaluate if the expansion affected the risk of having a short interpregnancy interval (IPI), a preventable risk factor for adverse pregnancy outcomes. Methods: We evaluated parous singleton births to mothers aged 19 or older from U.S. birth certificate data 2009–2018. We estimated the effect of residing in a state that expanded Medicaid access (expansion status determined at 60 days after the prior live birth) on the risk of having a short IPI (<12 months) using difference-in-differences (DID) methods in linear probability models. We stratified the analyses by maternal characteristics and county-level reproductive health care access. Results: Overall risk of short IPI was 14.9% in expansion states and 16.3% in non-expansion states. The expansion was not associated with a significant change in risk of having a short IPI (adjusted mean percentage point change 1.24 [-1.64, 4.12]). Stratified results also did not provide support for an association. Conclusions: ACA Medicaid expansion did not have an impact on risk of short IPI. Preventing short IPI may require more comprehensive policy interventions in addition to health care access.