Introduction: Despite increased attention on severe maternal morbidity and maternal mortality, scant research exists on adverse maternal outcomes in women with disabilities. This study compares the rates of severe maternal morbidity and maternal mortality in women with and without intellectual and developmental disabilities.

Methods: This study used 2004-2017 Healthcare Cost and Utilization Project Nationwide Inpatient Sample data. Analyses were conducted in 2019‒2020. The risk of severe maternal morbidity with and without blood transfusion and maternal mortality during delivery among women with and without intellectual and developmental disabilities were compared using modified Poisson regression analysis.

Results: This study identified 32,324 deliveries to women with intellectual and developmental disabilities. Per 10,000 deliveries, 566 deliveries with severe maternal morbidity occurred in women with intellectual and developmental disabilities compared with 239 in women without intellectual and developmental disabilities. Women with intellectual and developmental disabilities had greater risk of both severe maternal morbidity (risk ratio=2.36, 95% CI=2.06, 2.69) and nontransfusion severe maternal morbidity (risk ratio=2.95, 95% CI=2.42, 3.61) in unadjusted analyses, which was mitigated in adjusted analyses for sociodemographic characteristics (risk ratio=1.74, 95% CI=1.47, 2.06; risk ratio=1.85, 95% CI=1.42, 2.41) and the expanded obstetric comorbidity index (risk ratio=1.23, 95% CI=1.04, 1.44; risk ratio=1.31, 95% CI=1.02, 1.68). The unadjusted incidence of maternal mortality in women with intellectual and developmental disabilities was 284 per 100,000 deliveries, nearly 4-fold higher than in women without intellectual and developmental disabilities (69 per 100,000 deliveries; risk ratio=4.07, 95% CI=2.04, 8.12), and the risk remained almost 3-fold higher after adjustment for sociodemographic characteristics (risk ratio=2.86, 95% CI=1.30, 6.29) and the expanded obstetric comorbidity index (risk ratio=2.30, 95% CI=1.05, 5.29).

Conclusions: Women with intellectual and developmental disabilities are at increased risk of severe maternal morbidity and maternal mortality. These findings underscore the need for enhanced monitoring of the needs and maternal outcomes of women with intellectual and developmental disabilities in efforts to improve maternal health.