This study aims to estimate the association between maternal race and delivery gestational age among women with twin gestations.Study Design
Secondary analysis of a prospective, randomized control trial of 17-α hydroxyprogesterone caproate versus placebo for preterm birth (PTB) prevention in twin gestations. Non-Hispanic (NH) black and whites were included. Demographic and antenatal characteristics were compared. The primary outcome was delivery gestational age. Secondary outcomes included a composite of major neonatal morbidity. Kaplan-Meier curves estimated survival probabilities for delivery gestational age by race. Cox proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI).Results
A total of 535 women with twin gestations were included; 150 were NH black. NH blacks delivered earlier than NH whites (33.6 ± 4.8 weeks vs. 35.1 ± 3.5 weeks, p < 0.001). Differences in delivery gestational age between NH blacks and whites were consistent across gestation. In adjusted analyses, NH black race (HR: 1.24, 95% CI: 1.02-1.51), prior PTB (HR: 1.59, 95% CI: 1.15-2.19), and cerclage (HR: 3.90, 95% CI: 2.00-7.60) were associated with an increased risk of earlier delivery. Major neonatal morbidity was higher for NH blacks compared with NH whites (12.7 vs. 7.0%, p = 0.036).Conclusion
NH blacks with twin gestations have an increased risk of early delivery and neonatal morbidity compared with NH whites.