Trends and Risk Markers for Severe Maternal Morbidity and Other Obstetric Complications

Studies of obstetric quality of care have almost exclusively focused on severe maternal morbidity (SMM) and have rarely examined more common complications. This 2016-2018 retrospective, population-based cohort study analyzed maternal delivery outcomes at 127 Illinois hospitals. International Classification of Disease (ICD)-10 Revision codes were used to describe the incidence of SMM and route-specific complications. Poisson regression models were used to estimate the association of maternal sociodemographic, clinical, and hospital characteristics with the likelihood of coded complications. Among 421,426 deliveries, the SMM rate was 1.4% overall, 0.4% for vaginal, and 2.8% for cesarean delivery. Other complications were documented for 6.9% of women with vaginal and 10.0% of women with cesarean deliveries. While SMM rates were stable, vaginal delivery complications increased 5.9% from 2016 to 2018 and cesarean delivery complications increased 13.8%. Patient age, minority race and ethnicity, high poverty level, and preexisting and pregnancy-related clinical conditions were significantly associated with each complication outcome. Higher hospital delivery volume was associated with higher route-specific complications. SMM significantly underestimates the incidence of maternal complications. Complicated deliveries have much higher charges and length of stay, although ICD-10 coding intensity may influence incidence. New outcome measures based on more detailed clinical data and linked antepartum and postpartum care will be necessary to improve obstetric quality of care measurement.