Risk of interpersonal violence during and after pregnancy among people with schizophrenia: a population-based cohort study

BACKGROUND: Schizophrenia is associated with increased risk of experiencing interpersonal violence. Little is known about risk specifically around the time of pregnancy. METHODS: This population-based cohort study included all individuals (aged 15–49 yr) listed as female on their health cards who had a singleton birth in Ontario, Canada, between 2004 and 2018. We compared those with and without schizophrenia on their risk of an emergency department (ED) visit for interpersonal violence in pregnancy or within 1 year postpartum. We adjusted relative risks (RRs) for demographics, prepregnancy history of substance use disorder and history of interpersonal violence. In a subcohort analysis, we used linked clinical registry data to evaluate interpersonal violence screening and self-reported interpersonal violence during pregnancy. RESULTS: We included 1 802 645 pregnant people, 4470 of whom had a diagnosis of schizophrenia. Overall, 137 (3.1%) of those with schizophrenia had a perinatal ED visit for interpersonal violence, compared with 7598 (0.4%) of those without schizophrenia, for an RR of 6.88 (95% confidence interval [CI] 5.66–8.37) and an adjusted RR of 3.44 (95% CI 2.86–4.15). Results were similar when calculated separately for the pregnancy (adjusted RR 3.47, 95% CI 2.68–4.51) period and the first year postpartum (adjusted RR 3.45, 95% CI 2.75–4.33). Pregnant people with schizophrenia were equally likely to be screened for interpersonal violence (74.3% v. 73.8%; adjusted RR 0.99, 95% CI 0.95–1.04), but more likely to self-report it (10.2% v. 2.4%; adjusted RR 3.38, 95% CI 2.61–4.38), compared with those without schizophrenia. Among patients who did not self-report interpersonal violence, schizophrenia was associated with an increased risk for a perinatal ED visit for interpersonal violence (4.0% v. 0.4%; adjusted RR 6.28, 95% CI 3.94–10.00). INTERPRETATION: Pregnancy and postpartum are periods of higher risk for interpersonal violence among people with schizophrenia compared with those without schizophrenia. Pregnancy is a key period for implementing violence prevention strategies in this population.