Prenatal Care and Perinatal Regionalization for Congenital Heart Defects

Importance: Regionalization is a system by which neonates with congenital heart defects (CHDs) are directed to risk-appropriate levels of care. However, the role of prenatal care in delivery location remains unclear. Objective: To estimate associations between prenatal care adequacy and the likelihood of delivery at a pediatric cardiac center. Design, Setting, and Participants: This cross-sectional study examined retrospective data from the Illinois Department of Public Health's Adverse Pregnancy Outcomes Reporting System. Participants included neonates born with CHDs in Illinois from 2013 to 2021. Data were analyzed from November 2024 to May 2025. Exposures: Two binary exposure variables: (1) prenatal care initiation-none vs inadequate prenatal care (initiated after the fourth month or less than 50% of recommended visits) and (2) prenatal visit frequency-intermediate (50% to 79% of recommended visits) vs adequate (80% to 109% of recommended visits) or adequate plus (110% or more of recommended visits) prenatal care. Main Outcomes and Measures: Delivery at a pediatric cardiac center was the main outcome. Multivariable linear probability models estimated associations between prenatal care and delivery hospital, controlling for demographic and clinical characteristics. Regressions were stratified by CHD severity (eg, mild, moderate, and severe), as severe defects require intervention at a cardiac center within the first week of life. Results: Of 12 113 neonates with CHD, 3076 (25.4%) were born at a cardiac center and 1579 (13.0%) had severe CHD. Distribution for prenatal care initiation was: 272 (2.3%) had no prenatal care and 1617 (13.4%) had inadequate prenatal care. Distribution for prenatal visit frequency was: 1304 (10.8%) had intermediate prenatal care, 4217 (34.8%) had adequate prenatal care, and 4703 (38.8%) had adequate plus prenatal care. Prenatal care initiation was associated with a 10.5 (95% CI, 4.7 to 16.2) percentage point higher probability of delivery at a cardiac center for those with fetuses who had mild CHD and 30.2 (95% CI, 13.6 to 46.9) percentage point higher probability for severe CHD. For mild CHD, adequate plus prenatal care was associated with a lower probability of delivery at a cardiac center by 6.7 (95% CI, -4.0 to -9.4) percentage points compared with intermediate prenatal care. Prenatal visit frequency was not associated with delivery at a cardiac center for severe CHD. Conclusions and Relevance: In this cross-sectional study, delayed prenatal care initiation was associated with higher probability of delivery at a cardiac center, especially for severe CHD. More prenatal visits may help appropriately direct mild cases to noncardiac centers. Operationalization of regionalized CHD care requires consideration of many factors, including prenatal events.