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CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
Recording available 2/16-5/2
Recording available 2/16-5/2
AIUM Credit
AIUM Credit
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Foundation Awardee
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Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 1

Category: Health Equity/Community Health

Poster Session 1

(347) The increasing contribution of comorbidities to disparities in severe maternal mortality in the United States

Wednesday, February 11, 2026
10:30 AM - 12:00 PM  
Objective:
Recently, the reported incidence of severe maternal morbidity (SMM) has increased in the United States, and disparities in SMM rates between Black and White birthing people persist. Given that efforts to improve quality of delivery care would be expected to ameliorate these trends, we hypothesized that worsening disparities in the burden of comorbid conditions have led to increasing and more disparate rates of SMM.

Study Design:
We performed a retrospective cohort study of deliveries to Black and White birthing people between 2013 and 2022 using the National Inpatient Sample. The primary outcome was non-transfusion SMM. The maternal comorbidity index (MCI) score was generated using methods for comorbidity identification and weighting from previously published criteria. We performed a mediation analysis to evaluate the effect of the MCI on the disparity between race and non-transfusion SMM, allowing the effect of MCI on SMM to differ by race and calendar year.

Results:
There were 4,738,497 delivery hospitalizations during the study period. SMM rates increased in the years 2020-2022 compared to prior years (Figure 1A). Compared to White patients, Black patients experienced higher rates of non-transfusion SMM throughout the study period. MCI scores increased for both Black and White patients throughout the study period, with an enlarging disparity in mean scores (Figure 1B). For Black patients, the proportion of the racial disparity in non-transfusion SMM incidence attributable to the MCI increased from 30.6% in 2013 to 35.7% in 2022 (Figure 2).

Conclusion:
The MCI explains a substantial and growing disparity between Black and White birthing people in non-transfusion SMM rates in the United States, a trend likely exacerbated by the COVID-19 pandemic. Eradication of racial disparities in obstetric outcomes must continue to include efforts to not only eliminate racism in the intrapartum phase of care, but also to ameliorate the chronic impacts of racism on health preceding delivery.