Non-fatal self-harm and suicide following postpartum psychiatric emergency department visits: A population-based retrospective cohort study

•Following postpartum psychiatric ED visits, 4.3 % re-present with non-fatal self-harm.•Suicide occurs following 0.14 % of postpartum psychiatric ED visits.•Non-fatal self-harm and suicide risk are elevated when initial ED visits involve self-harm. In a population-based cohort of postpartum individuals in Ontario, Canada, this study aimed to determine the risk of non-fatal self-harm and suicide within one year of an initial postpartum psychiatric emergency department (ED) visit (2008–2020), and the key associated factors. Of 16,475 postpartum individuals with psychiatric ED visits, 714 (4.3 %) had non-fatal self-harm within one year, and 23 (0.15 %) died by suicide. Risk was substantially higher for those with self-harm at the initial presentation. Further efforts to connect individuals with postpartum psychiatric ED visits with needed inpatient care and outpatient follow-up are required to reduce non-fatal self-harm and suicide risk.