ObjectivesThis study aimed to evaluate the prevalence of obstetric and gynecologic (Ob/Gyn) hospitalists and determine if an association exists between the presence of Ob/Gyn hospitalists and severe maternal morbidity (SMM).MethodsThis observational study included data from hospitals listed in the USA TODAY’s 2019 article titled, “Deadly deliveries: Childbirth complication rates at maternity hospitals.” Telephone and email surveys of staff in these hospitals identified the presence or absence of continuous providers in the hospital 24 hours, 7 days a week (24/7 coverage) and the types of providers who are employed, then compared these responses with the SMM cited by USA TODAY.ResultsEight hundred ten hospitals were contacted, with participation from 614 labor and delivery units for a response rate of 75.8%. Fifty-seven percent of units were staffed with 24/7 coverage, with 46% of hospitals’ coverage primarily provided by an Ob/Gyn hospitalist and 54% primarily by a nonhospitalist OB/Gyn provider. The SMM and presence of 24/7 coverage increased with the level of neonatal care and delivery volume. Of hospitals with 24/7 coverage, those that primarily used Ob/Gyn hospitalists had a lower SMM for all mothers (1.7 versus 2.0, P = 0.014) and for low-income mothers (1.9 versus 2.30, P = 0.007) than those who primarily used nonhospitalist OB/Gyn providers.ConclusionsSevere maternal morbidity increases with delivery volume, level of neonatal care, and 24/7 coverage. Of hospitals with 24/7 coverage, units that staff with Ob/Gyn hospitalists have lower levels of SMM than those that use nonhospitalist Ob/Gyn providers.