Does maternal race or ethnicity modify the association between maternal psychiatric disorders and preterm birth?

Purpose: Preterm birth risk has been linked to maternal racial and ethnic background, particularly African American heritage; however, the association of maternal race and ethnicity with psychiatric disorders and preterm birth has received relatively limited attention. Methods: The Consortium on Safe Labor (2002–2008) is a nationwide U.S. cohort study with 223,394 singleton pregnancies. Clinical data were obtained from electronic medical records, including maternal diagnoses of psychiatric disorders. Relative risk (RR) and 95% confidence intervals (CI) were estimated for the association between maternal psychiatric disorders and preterm birth (<37 completed weeks) using log-binomial regression with generalized estimating equations. The interaction effect of maternal psychiatric disorders with race and ethnicity was also evaluated. Results: Non-Hispanic White (RR, 1.42; 95% CI, 1.35–1.49), Hispanic (RR, 1.44; 95% CI, 1.29–1.60), and non-Hispanic Black (RR, 1.21, 95% CI, 1.13–1.29) women with any psychiatric disorder were at increased risk for delivering preterm infants, compared with women without any psychiatric disorder. However, non-Hispanic Black women with any psychiatric disorder, depression, bipolar disorder, and schizophrenia had a significantly lower increase in preterm birth risk than non-Hispanic White women. Conclusions: Despite the significant association between maternal psychiatric disorders and preterm birth risk, psychiatric disorders did not appear to contribute to racial and ethnic disparities in preterm birth.