Paternal race and preterm birth.

Objective: The purpose of this study was to describe the contribution of paternal race and parental racial discordance to preterm birth

Study Design: We used a US natality cohort of 2,845,686 singleton births. Race was self-reported. Preterm birth was defined as a birth at <34 weeks of gestation.

Results: In considering white or black parents, black couples demonstrated greater odds of preterm birth (adjusted odds ratio, 2.4; 95% CI, 2.3-2.5) than white couples. Compared with white couples, black-white couples had increased odds of preterm birth. In black-white couples, the odds of preterm birth were greater if the mother was black (adjusted odds ratio, 1.7; 95% CI, 1.5-1.9) than if the father was black (adjusted odds ratio, 1.2; 95% CI, 1.1-1.3).

Conclusion: Regardless of maternal race, paternal black race is associated with increased odds of preterm birth. Additionally, among white-black couples, the odds of preterm birth are greater if the mother is black than if the father is black. These data support the notion of a differential contribution of race on preterm birth depending on the parent of origin.