Association of Postpartum Mental Illness Diagnoses with Severe Maternal Morbidity.

Background: This study aimed to determine whether birthing people who experience severe maternal morbidity (SMM) are more likely to be diagnosed with a postpartum mental illness. Materials and Methods: Using the Massachusetts All Payer Claims Database, this study used modified Poisson regression analysis to assess the association of SMM with mental illness diagnosis during the postpartum year, accounting for prenatal mental illness diagnoses and other patient characteristics. Results: There were 128,161 deliveries identified, with 55.0% covered by Medicaid. Of these, 3.1% experienced SMM during pregnancy and/or delivery hospitalization, and 20.1% had a mental illness diagnosis within 1 year postpartum. In adjusted regression analyses, individuals with SMM had a 10.6% increased risk of having any mental illness diagnosis compared to individuals without SMM, primarily due to an increased risk of a depression or post-traumatic stress disorder diagnosis among people with SMM than those without SMM. Conclusions: Individuals who experienced SMM had a higher risk of a mental illness diagnosis in the postpartum year. Given increases in SMM in the United States in recent decades, policies to mitigate mental health sequelae of SMM are urgently needed.