For a study, researchers sought to consolidate empirical research findings regarding the relationship between Medicaid expansion under the Affordable Care Act (ACA) and increased prenatal care access and usage among low-income women. They used PubMed (1966–present), EMBASE (Ovid), the Cumulative Index to Nursing and Allied Health (1982–present), the PAIS Index (ProQuest), Web of Science (1900–present), and the Cochrane Central Register of Controlled Trials to search MEDLINE. However, because the research focused on the relationship between Medicaid expansion under the ACA and perinatal care access and usage, which could not be studied in randomized controlled trials, was not searched.

Using Covidence, they conducted a thorough search of the research literature. Studies were considered eligible based on population data and had research designs that ensured the exposure (i.e., Medicaid expansion under the ACA) came before the perinatal care access or utilization outcome, had an appropriate comparison group, presented quantitative data, and examined pregnant or postpartum women. The search yielded 1,243 results from six bibliographic databases, with 855 abstracts assessed, 34 full-text publications screened for eligibility, and 9 suitable studies included in the systematic review.

Summary estimates, forest plots, funnel plots, and heterogeneity statistics were generated using Stata 16 software. Based on pooled data, random effects modeling found that Medicaid expansion was related with a 6.1% increase in Medicaid enrollment for pregnant women (95% CI 1.3–10.9%) and a 3.3% increase in perinatal care use (95% CI 0.2–6.3%). Medicaid expansion under the ACA was related to a slight but statistically significant increase in low-income women’s prenatal care access and usage.