Abstract 12316: Association of State Medicaid Expansion With Incidence of Gestational Diabetes Mellitus Among Nulliparous Individuals in the US, 2012-2019

Abstract

Introduction: The frequency of GDM and pregnancy-related complications of GDM are increasing in the United States. Detection and treatment are important to manage GDM and reduce the risk of pregnancy-related complications. The objective of this analysis was to assess whether expanding Medicaid, a state-level policy change that enhances access to care, was associated with changes in rates of GDM and outcomes among those with GDM. Methods: Data from nulliparous individuals aged 20-44 years with a first live birth from 30 states between 2012-2019 were included from the National Center for Health Statistics. The primary outcome, age-standardized incidence of GDM, was compared between Medicaid expansion states (N=16) and Medicaid non-expansion states (N=14) using a quasi-experimental analysis with difference-in-differences (DID) models. DID models utilized multivariate linear regression with random intercepts for state (to adjust for unobserved state-level fixed effects), fixed effect for year, and adjustment for state-level covariates including demographics, and health and economic indicators. Secondary outcomes included GDM complicated by preterm birth (≤36 weeks) and high (>4000 grams) or low (<2500 grams) birthweight infants. Results: Among 7,502,838 individuals, age-standardized rates of GDM increased in both Medicaid expansion (49.3 to 56.8 per 1000 births) and non-expansion states (48.6 to 52.7 per 1000 births). Expansion status was associated with a greater increase in rates of GDM (DID +4.32 [95% CI, +1.73 to +6.92] per 1000 births; Figure). Among individuals with GDM, rates of having a preterm birth or a high or low birthweight infant were not significantly different in expansion relative to nonexpansion states. Conclusions: Between 2012-2019, states that expanded Medicaid had a significantly greater increase in incidence of GDM. However, among those with GDM, rates of preterm birth and high or low birthweight did not differ by expansion status.