Postpartum psychiatric hospital admissions: A population-based study from British Columbia, Canada

The risk of psychiatric hospitalization increases in the year postpartum, and rates have been rising. However, data describing these admissions is limited. In this retrospective, population-based study of all deliveries between 2015-2019 in British Columbia (BC), Canada, we linked BC perinatal data registry with other health services data, including all hospital admissions. Rates, characteristics, and risk factors for postpartum psychiatric hospital admissions were analyzed using descriptive statistics and logistic regression modeling. Following 189,530 deliveries, there were 812 postpartum psychiatric admissions (∼4/1000 deliveries). The most common indications for postpartum admission were depression (n=233[28.7%]) and substance-related disorders (n=234[28.8%]). These hospitalizations were short (median=3 days, IQR(Q1-Q3)=1-8), and relatively late (median=5.5 months postpartum, IQR(Q1-Q3)=68.5-251 days). Hospitalizations for psychosis and bipolar disorder occurred much later than expected (psychosis: median=111 days postpartum (IQR=32-213); bipolar disorder: median=118 days (IQR=42-230)). The risk factors most associated with these admissions were younger age, especially age<20 (aOR=5.01, 95% CI:3.60-6.98), receiving treatment for schizophrenia during pregnancy (aOR=4.21, 95% CI:2.42-7.34), and a psychiatric diagnosis during pregnancy (aOR=3.58, 95% CI:2.30-5.58). These results show that those at high risk of severe postpartum psychiatric illness were young, took antidepressants during pregnancy, and had a recent psychiatric illness. This knowledge could support early intervention and avoid the need for hospitalization. This research should be replicated and expanded to explore gaps in the healthcare system for severe postpartum psychiatric illness.