ABSTRACT: The effect of the Affordable Care Act (ACA) dependent coverage provision on pregnancy-related health care and health outcomes is unknown.To determine whether the dependent coverage provision was associated with changes in payment for birth, prenatal care, and birth outcomes.Retrospective cohort study, using a differences-in-differences analysis of individual-level birth certificate data comparing live births among US women aged 24 to 25 years (exposure group) and women aged 27 to 28 years (control group) before (2009) and after (2011-2013) enactment of the dependent coverage provision. Results were stratified by marital status.The dependent coverage provision of the ACA, which allowed young adults to stay on their parent's health insurance until age 26 years.Primary outcomes were payment source for birth, early prenatal care (first visit in first trimester), and adequate prenatal care (a first trimester visit and 80% of expected visits). Secondary outcomes were cesarean delivery, premature birth, low birth weight, and infant neonatal intensive care unit (NICU) admission.The study population included 1?379?005 births among women aged 24-25 years (exposure group; 299?024 in 2009; 1?079?981 in 2011-2013), and 1?551?192 births among women aged 27-28 years (control group; 325?564 in 2009; 1?225?628 in 2011-2013). From 2011-2013, compared with 2009, private insurance payment for births increased in the exposure group (36.9% to 35.9% [difference, -1.0%]) compared with the control group (52.4% to 51.1% [difference, -1.3%]), adjusted difference-in-differences, 1.9 percentage points (95% CI, 1.6 to 2.1). Medicaid payment decreased in the exposure group (51.6% to 53.6% [difference, 2.0%]) compared with the control group (37.4% to 39.4% [difference, 1.9%]), adjusted difference-in-differences, -1.4 percentage points (95% CI, -1.7 to -1.2). Self-payment for births decreased in the exposure group (5.2% to 4.3% [difference, -0.9%]) compared with the control group (4.9% to 4.3% [difference, -0.5%]), adjusted difference-in-differences, -0.3 percentage points (95% CI, -0.4 to -0.1). Early prenatal care increased from 70% to 71.6% (difference, 1.6%) in the exposure group and from 75.7% to 76.8% (difference, 0.6%) in the control group (adjusted difference-in-differences, 0.6 percentage points [95% CI, 0.3 to 0.8]). Adequate prenatal care increased from 73.5% to 74.8% (difference, 1.3%) in the exposure group and from 77.5% to 78.8% (difference, 1.3%) in the control group (adjusted difference-in-differences, 0.4 percentage points [95% CI, 0.2 to 0.6]). Preterm birth decreased from 9.4% to 9.1% in the exposure group (difference, -0.3%) and from 9.1% to 8.9% in the control group (difference, -0.2%) (adjusted difference-in-differences, -0.2 percentage points (95% CI, -0.3 to -0.03). Overall, there were no significant changes in low birth weight, NICU admission, or cesarean delivery. In stratified analyses, changes in payment for birth, prenatal care, and preterm birth were concentrated among unmarried women.In this study of nearly 3 million births among women aged 24 to 25 years vs those aged 27 to 28 years, the Affordable Care Act dependent coverage provision was associated with increased private insurance payment for birth, increased use of prenatal care, and modest reduction in preterm births, but was not associated with changes in cesarean delivery rates, low birth weight, or NICU admission.
