The Influence of Maternal and Paternal Race on Perinatal Outcomes

Objective: To examine associations between maternal-paternal racial pairings and adverse perinatal outcomes in the United States. Study Design: We conducted a retrospective population-based cohort study using 2016–2023 U.S. birth certificate data from the CDC National Vital Statistics System. Singleton live births with complete data on maternal and paternal race were included. Parental race was categorized as non-Hispanic White, non-Hispanic Black, Hispanic, or Asian, resulting in 16 racial dyads. Outcomes included preterm birth (PTB, <37 weeks), hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), and small for gestational age (SGA, <10th percentile). Adjusted relative risks (aRRs) were estimated using multivariable Poisson regression with robust error variance, adjusting for maternal age, body mass index, parity, insurance status, nativity, chronic hypertension, pregestational diabetes, smoking, and social vulnerability index. Results: Of 26,284,090 births, 12,595,260 (47.9%) had White fathers, 9,147,469 (34.8%) Hispanic, 3,131,956 (11.9%) Black, and 1,409,405 (5.4%) Asian fathers. Compared to White fathers, PTB risk was higher with Black (aRRs 1.09-1.21) and Hispanic fathers (1.14-1.31), and lower among Asian fathers (0.84-0.93) regardless of maternal race. HDP risk was consistently lower among Asian (0.72-0.87) and Black fathers (0.86-0.93), while associations with Hispanic fathers were inconsistent. GDM risk was lower among Black fathers (0.87-0.94). For Hispanic fathers, GDM risk decreased among White and Black mothers but increased in Hispanic mothers. Asian fathers were associated with higher GDM risk compared to White fathers only among Asian mothers. SGA risk was higher for all non-White paternal groups, highest with Asian fathers (1.40-1.86). Conclusion Paternal race was associated with perinatal risk. Non-White paternal race was associated with higher risks of PTB and SGA, whereas risks of HDP and GDM varied according to the specific maternal–paternal racial pairing. Keywords: Perinatal outcomes, Paternal race, Maternal-paternal racial pairing, Interracial couples, Preterm birth, Hypertensive disorders of pregnancy, Gestational diabetes mellitus, Small for