Premature births increase neonatal morbidity and mortality. Previous studies have only looked at risks associated with the mother's race. The objective of this study was to determine risks of prematurity based on combinations of maternal and paternal origin for Hispanic, non-Hispanic white, non-Hispanic black, and Asian parents.
This is a retrospective cohort analysis of the 2013 CDC birth certificate data for nulliparous, singleton pregnancies. Prematurity risks (delivery under 37 weeks gestation) were calculated for 16 parental combinations for Hispanic (H), non-Hispanic white (NHW), non-Hispanic black (NHB), and Asian (A) mothers and fathers. Infants born to parents that were both non-Hispanic white served as reference (RR=1).
The study population consisted of 1,246,140 deliveries. The distribution among mothers was: NHW: 762,195; H: 252,730; NHB: 137,973; A: 93,242 and among fathers: NHW: 746,644; H: 251,870; NHB: 161,170; A: 86,456. The risk of prematurity nearly doubled when both parents were non-Hispanic black as compared to mothers that were NHW and fathers that were A (14.9% versus 7.37%; RR 1.9; 95% CI 1.76–2.03, P<.0001). Across all maternal groups, prematurity risks dropped significantly when the father was Asian (Range: 7.37%–11.56%) and increased when the father was non-Hispanic black (Range: 10.74%–14.9%).
Our study shows that the father's race and origin significantly determines the risk of prematurity. Across all groups, infants of Asian fathers had consistently lower prematurity risks while infants of non-Hispanic black fathers had significantly increased prematurity risks. A father's race and origin should be included when assessing prematurity risks.
Weill Medical College of Cornell University, New York, NY
Financial Disclosure: The authors did not report any potential conflicts of interest.