(WITHDRAWN) Comparing Public and Private Insurance for Pregnant Women: Medicaid Versus Marketplace Eligibility

Background and Purpose: There are vast differences in provider reimbursements for pregnancy care and patient cost-sharing between Medicaid and private insurance, which can lead to inequities in access, utilization, and health outcomes. The Affordable Care Act increased Medicaid eligibility for families up to 138% of the federal poverty level (FPL) in all states that chose to expand their Medicaid programs. The ACA also included subsidized private coverage for families with incomes between 100–400% of the FPL for purchase on the Marketplace exchanges. As a result, families with incomes between 100-138% of the FPL either gained Medicaid eligibility if they lived in a state that adopted Medicaid expansion, or gained eligibility for subsidized private coverage in the Marketplace if they lived in a non-expansion state. This study aims to examine if differences in eligibility for Medicaid versus private Marketplace coverage for low-income women under the ACA are associated with differential access to maternal care and pregnancy outcomes and racial disparities in these outcomes.

Methods: This study will use a difference-in-difference model to compare the effects of gaining Medicaid eligibility versus Marketplace eligibility on maternal insurance coverage, prenatal care utilization, and childbirth outcomes using data from the Pregnancy Risk Assessment Monitoring System. Analyses are limited to women whose incomes are 100-138 percent of the federal poverty level between the years 2011-2017. The sample includes 13 states and New York City, with a total sample of 11,333 women. Outcomes include maternal insurance prior to and after pregnancy, prenatal care initiation and adequacy, and preterm and low birthweight deliveries. Difference-in-difference-in-difference models are used to examine differential outcomes by race/ethnicity with wild cluster standard errors by state.

Results: Medicaid eligibility relative to Marketplace eligibility for low-income pregnant women was associated with increased preconception Medicaid coverage by 6.2 percentage points (p=0.08), decreased preconception employer-sponsored insurance by 3.3 percentage points (p=0.08), and increased postpartum Medicaid coverage by 8.3 percentage points (p=0.05). Relative to non-Hispanic white women, Black women had significantly less postpartum Medicaid by 7.2 percentage points (p= 0.008). Medicaid eligibility relative to Marketplace eligibility was associated with decreased preterm deliveries by 2.1 percentage points (p=0.04) and increased first trimester prenatal care by 3.0 percentage points (p=0.02). Relative to non-Hispanic white women, Hispanic women had significantly higher adequate prenatal care consumption by 1.4 percentage points (p=0.04). There was no significant difference in the association between Medicaid/marketplace and the outcomes by race/ethnicity for prenatal care initiation, preterm births, or low birthweight deliveries.

Conclusions and Implications: Overall, Medicaid versus Marketplace eligibility was associated with increased postpartum Medicaid coverage, improved prenatal care initiation, and decreased preterm deliveries, with some racial/ethnic differences in maternal insurance type but no differences in prenatal or birth outcomes. Medicaid eligibility was associated with larger preconception Medicaid improvements than in relative preconception employer-sponsored decreases, suggesting overall increases in preconception Medicaid. Understanding differences in care access and outcomes by insurance eligibility could allow policymakers to target coverage policies for pregnant women to decrease disparities in maternal health outcomes and inequities in maternal care access.