Social Determinants of Health and Disparities in Pregnancy Outcomes

To examine the extent to which racial and ethnic disparities in adverse pregnancy outcomes between non-Hispanic Black women and non-Hispanic White women may be explained by social determinants of health (SDoH).

This study was a secondary analysis of a prospective cohort study (nuMoM2b [Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be]) that enrolled 10,038 nulliparous individuals with singleton pregnancies. This analysis included only individuals who identified as non-Hispanic Black or non-Hispanic White. We used the nonlinear extension of the Oaxaca-Blinder decomposition based on logistic regression to estimate the percentage contribution of SDoH to racial and ethnic disparity in preterm birth (PTB) and preeclampsia. Eleven SDoH variables in the models covered various SDoH domains (ie, sociodemographic, psychological, behavioral, social relationship, and health care access and quality).

Of 10,038 individuals, 1,321 non-Hispanic Black and 5,762 non-Hispanic White individuals composed the study population. Compared with non-Hispanic White individuals, non-Hispanic Black individuals had 3.9% (95% CI, 2.0-5.7) and 4.1% (95% CI, 2.2-6.0) higher frequencies of PTB and preeclampsia, respectively. A large proportion of disparities between non-Hispanic White women and non-Hispanic Black women in PTB (56.4%; 95% CI, 2.9-100.0) and preeclampsia (71.2%; 95% CI, 17.5-100.0) may be explained by SDoH.

A large percentage of the racial and ethnic disparities between non-Hispanic Black and non-Hispanic White individuals in PTB and preeclampsia were explained by SDoH. These findings underscore the contribution of SDoH to racial and ethnic disparities in adverse pregnancy outcomes and point to intervention targets to reduce racial health disparities.