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.
We searched MEDLINE, CINAHL, and the Social Sciences Citation Index through November 2022.
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.
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.
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.
