Maternal nativity and risk of adverse perinatal outcomes among Black women residing in California, 2011-2017.

Objective Examine the risk of adverse perinatal outcomes among the United States (US)-born and foreign-born Black women in California. Study design The study comprised all singleton live births to Black women in California between 2011 and 2017. We defined maternal nativity as US-born or foreign-born. Using Poisson regression, we computed risk ratios (RR) and 95% confidence intervals (CI) for three adverse perinatal outcomes: preterm birth, small for gestational age deliveries, and infant mortality. Results Rates of adverse perinatal outcomes were significantly higher among US-born Black women. In adjusted models, US-born Black women experienced an increased risk of preterm birth (RR 1.51, 95% CI 1.39, 1.65) and small for gestational age deliveries (RR 1.52, 95% CI 1.41, 1.64), compared to foreign-born Black women. Conclusions Future studies should consider experiences of racism across the life course when exploring heterogeneity in the risk of adverse perinatal outcomes by nativity among Black women in the US.