The Impact of Increased Medicaid Eligibility During Pregnancy on Medicaid Utilization and Gestational Age.

Objective: To assess the impact of increased Medicaid income eligibility during pregnancy on payment source for prenatal care and birth and on gestational age at birth (GAb).

Study setting and design: We performed a quasi-experimental, difference-in-differences study comparing two increases in Medicaid income eligibility during pregnancy to two control states with data from 2007 to 2010: (Dyad 1) Ohio (expanded from 150% to 200% of the Federal Poverty level [FPL]) versus Pennsylvania and (Dyad 2) Wisconsin (185% to 250% FPL) versus Michigan. We performed multinomial logistic regression to assess the impact of increased Medicaid eligibility on the following key outcome variables: payment source for prenatal care and birth and GAb.

Data sources and analytic sample: We utilized CDC Pregnancy Risk Assessment Monitoring System (PRAMS) data (2007-2010) and limited analysis to singleton, in-state live births. After re-weighting for PRAMS survey design, our analytical sample represented about 540,000 births.

Principal findings: In the higher-income Wisconsin-Michigan dyad, increased Medicaid eligibility during pregnancy significantly increased exclusive Medicaid coverage for prenatal care (7.0%, 95% CI 2.9% to 11.1%) and birth (8.3%, 4.3% to 12.4%). Simultaneously, private insurance coverage dropped for prenatal care (-4.0%, -7.7% to -0.3%) and birth (-3.7%, -7.2% to -0.2%) while self-payment decreased only for birth (-1.8%, -3.5% to -0.2%). In the lower-income Ohio-Pennsylvania dyad, the only statistically significant effects on payment source were decreases in the likelihood of a payment source of other for prenatal care (-3.3%, -6.2% to -0.3%) and birth (-4.7%, -7.9% to -1.6%). There were no statistically significant effects on GAb across both dyads.

Conclusions: Increased Medicaid eligibility during pregnancy for individuals of higher income seems to improve utilization of exclusive Medicaid with diminished uninsurance but also less private insurance after accounting for indicators of socioeconomic advantage but has no clear impact on GAb. Medicaid policy should balance reducing uninsurance with directing scarce resources to high-risk individuals.