We examined severe maternal morbidity (SMM) among birthing people with opioid use disorder (OUD) and evaluated the extent to which differences in SMM exist by race and ethnicity.
We performed a retrospective cohort study using hospital discharge data for all Massachusetts births between 2016 and 2020. SMM rates for all SMM indicators, except transfusions, were computed for those diagnosed with and without OUD. Multivariable logistic regression was used to examine the association between OUD and SMM after adjusting for patient and hospital characteristics, including race and ethnicity.
Among 324,012 childbirths, the SMM rate was 148 (95% confidence interval [CI]. 115-189) per 10,000 childbirths among birthing people with OUD compared with 88 (95% CI, 85-91) for those without. In adjusted models, both OUD and race/ethnicity were significantly associated with SMM. Birthing people with OUD had 2.12 (95% CI, 1.64-2.75) times the odds of experiencing an SMM event compared with those without. Non-Hispanic Black and Hispanic birthing people were at 1.85 (95% CI, 1.65-2.07) and 1.26 (95% CI, 1.13-1.41) higher odds of experiencing SMM compared with non-Hispanic White birthing people. Among birthing people with OUD, the odds of SMM were not significantly different between birthing people of color and non-Hispanic White individuals.
Birthing people with OUD are at an elevated risk of SMM, underscoring the need for improved access to OUD treatment and increased support. Perinatal quality improvement collaboratives should measure SMM in bundles aimed at improving outcomes for birthing people with OUD.

Published by Elsevier Inc.