Up-to-date data on population-level risk factors for postpartum psychosis is limited though increasing substance use disorders, psychiatric disorders, autoimmune disorders, and other medical comorbidities in the obstetric population may be contributing to increased baseline risk for postpartum psychosis.
To determine trends in and risk factors for postpartum psychosis during delivery hospitalizations and postpartum readmissions.
Analyzing the 2016-2019 Nationwide Readmission Database, this repeated cross sectional study identified diagnoses of postpartum psychosis during delivery hospitalizations and postpartum readmissions within 60 days of discharge. The relationship between demographic, clinical, and hospital level factors present at delivery and postpartum psychosis was analyzed with logistic regression models with adjusted odds ratios (aORs) with 95% CIs as measures of association. Separate models were created for postpartum psychosis diagnoses at delivery and during a postpartum readmission. Temporal trends in diagnoses were analyzed with joinpoint regression to determine the average annual percent change (AAPC) with 95% CIs.
Of 12,334,506 deliveries in the analysis 13,894 (1.1 per 1000) carried a diagnosis of postpartum psychosis during the delivery hospitalization and 7,128 (0.6 per 1000) had a 60-day postpartum readmission with postpartum psychosis. Readmissions with postpartum psychosis increased significantly over the study period (p=0.046). The majority of readmissions with a postpartum psychosis diagnosis occurred 0-10 days (43% of readmissions) or 11-20 days after discharge (18% of readmissions). Clinical factors with the highest adjusted odds for postpartum psychosis readmission included delivery postpartum psychosis (aOR 5.8, 95% CI 4.2, 8.0), depression disorder (aOR 3.7, 95% CI 3.3, 4.2), bipolar spectrum disorder (OR 2.9, 95% CI 2.3, 3.5), and schizophrenia spectrum disorder (aOR 2.9, 95% CI 2.1, 4.0). In models analyzing postpartum psychosis diagnoses at delivery, risk factors associated with the highest odds included anxiety disorder (aOR 3.9, 95% CI 3.5, 4.2), schizophrenia spectrum disorder (aOR 2.5, 95% CI 1.9, 3.4), bipolar disorder (aOR 1.8, 95% CI 1.6, 2.1), stillbirth (OR 3.6, 95% CI 3.1, 4.2), and substance use disorder (OR 1.7, 95% CI 1.6, 1.9). Chronic conditions such as pregestational diabetes, obesity, and substance use were also associated with delivery and readmission postpartum psychosis.
Postpartum psychosis is increasing during postpartum readmissions and associated with a wide range of obstetric and medical comorbidities. Close follow up care after delivery for other medical and obstetric diagnoses may represent an opportunity to identify postpartum psychiatric conditions including postpartum psychosis.

Copyright © 2023. Published by Elsevier Inc.