Amer J Perinatol 2017; 34(11): 1065-1071
DOI: 10.1055/s-0037-1603764
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Racial Disparities in Delivery Gestational Age among Twin Pregnancies

Jacqueline H. Grant1, Catherine J. Vladutiu1, Tracy A. Manuck1
  • 1Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina
Further Information

Publication History

02 May 2017

05 May 2017

Publication Date:
07 June 2017 (eFirst)


Objective 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.


Non-Hispanic black women with twin gestations deliver earlier than non-Hispanic white women.


This article was presented as a poster at the 2017 Annual Meeting of the Society for Maternal-Fetal Medicine; January 26, 2017; Las Vegas, NV. Final abstract ID# 149.