Racial Disparities in the Risk for Preterm Birth as a Function of Maternal Age [25C

Abstract

INTRODUCTION: We sought to investigate the impact of maternal age on the risk for preterm birth (PTB) and whether it is affected by maternal race. METHODS: This retrospective cohort study utilized the US Live Birth database from the CDC for the years 2016–2017. Nulliparous women with in-hospital, singleton PTBs between 22–37 weeks of gestation were eligible for analysis. Exclusion criteria included fetal anomalies and maternal hypertension and/or diabetes complicating pregnancy. Maternal race was characterized as non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic and Asian. The rate of PTB was calculated among each racial group across all maternal ages. Chi-squared analysis was used to compare the prevalence of PTB per maternal age across the different racial groups. RESULTS: The cohort included 199,643 PTBs. Of those, 102,815 (51.5%) were NHW, 37,844 (19%) were NHB, 44,472 (22.3%) were Hispanic and 14,512 (7.2%) were Asian. Across all racial groups, the rate of PTB is higher at the extremes of maternal age, with the highest risk occurring in women >35 years old (P<.05). The difference in PTB rates between NHB and all other racial groups increased as a function of age (P<.05). CONCLUSION: The rate of PTB is higher in the extremes of maternal age for all races. At each maternal age interval, a racial disparity in PTB rates exists and increases as maternal age increases. Clinicians should be aware of this disparity in the risk of PTB and the impact of extremes of the maternal age when counseling patients during pregnancy.