Cross-Generational Contributors to Preterm Birth in California: Singletons Based on Race/Ethnicity

Abstract

Objective Multiple studies have examined cross-generational patterns of preterm birth (PTB), yet results have been inconsistent and generally focused on primarily white populations. We examine the cross-generational PTB risk across racial/ethnic groups. Study Design Retrospective study of 388,474 grandmother–mother–infant triads with infants drawn from birth registry of singleton live births between 2005 and 2011 in California. Using logistic regression (odds ratios [ORs] and confidence intervals [CIs]), we examined the risk of preterm delivery by gestational age, sociodemographic, socioeconomic, and obstetric clinical characteristics stratified by maternal race/ethnicity. Results The risk of having a preterm infant <32 weeks was greater for women born at <32 weeks (OR: 2.09, 95% CI: 1.62–2.70) and 32 to 36 weeks (OR: 1.51, 95% CI: 1.35–1.70). This increased risk of preterm delivery was present among women in all race/ethnicity groups (white [AOR: 2.00, 95% CI: 1.52–2.63), black [AOR: 1.79, 95% CI: 1.37–2.34], Hispanic [AOR: 2.39, 95% CI: 2.05–2.79], and Asian [AOR: 2.12, 95% CI: 1.20–3.91]), with hypertension as the only consistent risk factor associated with increased risk of preterm delivery. Conclusion Our findings suggest a cross-generational risk of PTB that is consistent across race/ethnicity with hypertension as the only consistent risk factor.