• Included study exposures broadly covered social-structural determinants of health for pregnant and birthing people; however, the identified determinants still represent only a subset of potential social-structural determinants of interest and did not address interdependence of risk factors, including biological/medical risk factors.
• Limited depth and quality of available research within each risk factor domain—including racism and other forms of discrimination—impeded our ability to understand pathways connecting social-structural determinants of health and maternal health outcomes.
• We found an unexpectedly large volume of research on violence and trauma relative to other potential social determinants of health for pregnant people.
• For outcome domains, depression/other mental health outcomes represented a large proportion of the health outcomes captured.
• We found one study investigating patterns of intersecting social-structural determinants of health that is an exemplar of new approaches to risk factor research.
• Rarely did studies report the excess risk attributable to a specific exposure. Of note, very recent studies, mostly limited geographically, reported:
  • Income inequality was associated with a 14 percent increase in excess risk of death for Black pregnant women relative to White women in Virginia; prolonged 5-year income inequality was associated with a 20 percent increase.
  • Hispanic birthing women were more likely to deliver at hospitals with higher risk-adjusted severe maternal morbidity; delivery location may contribute up to 37 percent of ethnic disparity in severe maternal morbidity in New York City.
  • Combined race and income segregation was associated with increased severe maternal morbidity in birthing women in New York City; delivery hospitals accounted for 35 percent of the attributable risk, and 50 percent of comorbidities.
  • Nationally, if rural Indigenous birthing women experienced severe maternal morbidity and mortality at the same rate as urban white women, they would see a 49 percent reduction in cases.

Objective. The purpose was to review available evidence of risk factors associated with maternal morbidity and mortality in the United States during the prenatal and postpartum periods to inform a National Institutes of Health Pathways to Prevention Workshop: Identifying Risks and Interventions to Optimize Postpartum Health, held November 29–December 1, 2022.

Data sources. We searched MEDLINE^®, CINAHL^®, and the Social Sciences Citation Index through November 2022.

Review methods. We searched for observational studies examining exposures related to social and structural determinants of health and at least one health or healthcare-related outcome for pregnant and birthing people. We extracted basic study information and grouped studies by social and structural determinants of health domains and maternal outcomes. We prioritized studies according to study design and rigor of analytic approaches to address selection bias based on the ROBINS-E. We summarize all included studies and provide additional descriptions of direction of association between potential risk exposures and outcomes.

Results. We identified 8,378 unique references, with 118 included studies reporting social and structural determinants of health associated with maternal health outcomes. Studies covered risk factors broadly, including identity and discrimination, socioeconomic, violence, trauma, psychological stress, structural/institutional, rural/urban, environment, comorbidities, hospital, and healthcare use factors. However, the risk factors we identified represent only a subset of potential social and structural determinants of interest. We found an unexpectedly large volume of research on violence and trauma relative to other potential exposures of interest for pregnant people. Outcome domains included maternal mortality, severe maternal morbidity, hypertensive disorders, gestational diabetes, cardio/metabolic disorders, weathering (the physiological effect of premature aging caused by chronic stressful experiences), depression, other mental health or substance use disorders, and cost/healthcare use outcomes. Depression/other mental health outcomes represented a large proportion of medical outcomes captured. Risk of bias was high, and rarely did studies report the excess risk attributable to a specific exposure.

Conclusions. Identifying risk factors pregnant and birthing people face is vitally important. Limited depth and quality of available research within each social and structural determinant of health impeded our ability to outline specific pathways, including risk factor interdependence. While more recently published literature showed a trend toward increased rigor, future research can emphasize techniques that estimate the causal impacts of risk factors. Improved reporting in studies, along with organized and curated catalogues of maternal health exposures and their presumed mechanisms, would make it easier to examine exposures in the future. In the longer term, the field could be advanced by datasets designed to more fully capture the data required to robustly examine racism and other social and structural determinants of health, in combination with their intersections and feedback loops with other biologic/medical risk factors.

Neerland C, Slaughter-Acey J, Behrens K, et al. An Evidence Map for Social and Structural Determinants for Maternal Morbidity and Mortality: A Systematic Review. Obstetrics & Gynecology. 2023 Dec 21. [Epub ahead of print.] DOI: 10.1097/AOG. 0000000000005489.

Slaughter-Acey J, Behrens K, Claussen AM, Usset T, Neerland C, Bilal-Roby S, Bashir H, Westby A, Wagner B, Dixon M, Xiao M, Butler M. Social and Structural Determinants of Maternal Morbidity and Mortality: An Evidence Map. Comparative Effectiveness Review No. 264. (Prepared by the Minnesota Evidence-based Practice Center under Contract No. 75Q80120D00008.) AHRQ Publication No. 23(24)-EHC014. Rockville, MD: Agency for Healthcare Research and Quality; December 2023. DOI: https://doi.org/10.32970/AHRQEPCCER264. Posted final reports are located on the Effective Health Care Program search page.