This study assessed racial and ethnic disparities in severe maternal mortality during delivery through 6 weeks postpartum, before and during the COVID pandemic, in a statewide Medicaid population. This retrospective, population-based, cohort study used Medicaid claims data linked to birth certificates from the Michigan Department of Health and Human Services Health Services Data Warehouse that included all individuals giving birth between January 1, 2017, and October 31, 2021, in Michigan who had Medicaid insurance during the month of childbirth. The SMM rate increased more during the COVID pandemic for Black (1.36 [1.26-1.46]) compared to White individuals (1.17 [1.09-1.26], p-value<0.01 Black vs White). The Black-White and Hispanic-White disparities in severe maternal morbidity, already high in the Medicaid population, widened during the COVID pandemic. Multilevel interventions are needed to reduce disparities in maternal morbidity and mortality.

Conflict of interest disclosure No conflicts to disclose.

The authors have declared no competing interest.

The study received financial support from the National Institute on Minority Health and Health Disparities (NIMHD; R01 MD016003 and U54HD113291; Principal Investigators Johnson and Meghea). NIMHD had no role in the design and conduct of the study; collection, management, analysis, or interpretation of the data; or preparation or decision to submit the manuscript for publication.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This retrospective, population-based, cohort study was exempt from review by the Michigan State University Institutional Review Board.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data used in the present study can be made available upon reasonable request to the authors