Associations between individual and structural level racism and gestational age at birth in the Nulliparous Pregnancy Outcomes Study: Monitoring mothers-to-be.

The purpose of this study was to investigate the associations between multilevel racism and gestational age at birth among nulliparous non-Hispanic Black, non-Hispanic White and Hispanic women. We conducted a secondary analysis of data of the nuMoM2b Study (2010-2013) to examine the associations between individual and structural-level experiences of racism and discrimination and gestational age at birth among nulliparous women (n=7,732) at eight sites across the U.S. Measures included the individual Experiences of Discrimination (EOD) scale and the Index of Concentration (ICE) at the Extremes to measure structural racism. After adjustment,we observed a significant individual and structural racism interaction on gestational length (p=0.03). In subgroup analyses, we found that among these with high EOD scores, women who were from households concentrated in the more privileged group had significantly longer gestations (β = 1.07, 95% CI: 0.24, 1.90). Women who reported higher EOD scores and more economic privilege had longer gestations, demonstrating the moderating effect of ICE as a measure of structural racism. In conclusion, ICE may represent a modifiable factor in the prevention of adverse birth outcomes in nulliparas.