BACKGROUND: Almost 50% of women with schizophrenia become pregnant. Little is known about their psychiatric service use patterns during or shortly after pregnancy.METHODS: Using health administrative data, we identified 1,433 women in Ontario, Canada, with schizophrenia (ICD-9, ICD-10, or DSM-IV-TR) who had a live birth delivery from January 2003 through March 2011 and described their use of acute psychiatric care services including hospitalizations, emergency department visits not requiring hospitalization, and self-harm-related emergency department visits during pregnancy and in the first year postpartum. Incidence rates of psychiatric hospitalization during pregnancy, and also within 1 year postpartum, were each compared to the incidence rate of psychiatric hospitalization in the 1-year period before conception. Results are presented as incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Similar comparisons were made for psychiatric emergency department visits not requiring hospitalization, as well as for self-harm-related emergency department visits.RESULTS: About 12% of the women had at least 1 psychiatric hospitalization during pregnancy, and 19% in the first year postpartum. About 10% had at least 1 psychiatric emergency department visit without hospitalization during pregnancy, and 16% had at least 1 emergency department visit postpartum. Self-harm-related emergency department visits were rarer, affecting only about 1% of the women in each time period. Relative to that in the 1-year period before conception (50 per 100 person-years), the incidence rate of psychiatric hospitalizations was lower during pregnancy (25 per 100 person-years), which is equivalent to an IRR of 0.50 (95% CI, 0.43-0.60). While the IRR of psychiatric hospitalizations was lower over the entire 1-year period postpartum (0.66; 95% CI, 0.57-0.76), it was transiently higher in the first 9 days postpartum (3.59; 95% CI, 2.74-4.69) and then waned by days 10 to 29 postpartum (0.87; 95% CI, 0.56-1.24). Emergency department visits for psychiatric and self-harm reasons were consistently lower during pregnancy and postpartum compared to the year before conception.CONCLUSIONS: Psychiatric hospitalizations and emergency department visits are not uncommon for women with schizophrenia during pregnancy and the postpartum period. However, except for a brief period after delivery, women with schizophrenia are at relatively lower risk of requiring acute psychiatric inpatient and emergency care during and 1 year after pregnancy compared to the 1-year period prior to conception. This is key prognostic information for women with schizophrenia, their families, and providers who counsel them regarding pregnancy, motherhood, and management of schizophrenia. Identifying women at risk of requiring acute psychiatric services in the perinatal period warrants further investigation.