BACKGROUND: Death by suicide during the perinatal period has been understudied in Canada. We examined the epidemiology of and health service use related to suicides during pregnancy and the first postpartum year.METHODS: In this retrospective, population-based cohort study, we linked health administrative databases with coroner death records (1994-2008) for Ontario, Canada. We compared sociodemographic characteristics, clinical features and health service use in the 30 days and 1 year before death between women who died by suicide perinatally, women who died by suicide outside of the perinatal period and living perinatal women.RESULTS: The perinatal suicide rate was 2.58 per 100 000 live births, with suicide accounting for 51 (5.3%) of 966 perinatal deaths. Most suicides occurred during the final quarter of the first postpartum year, with highest rates in rural and remote regions. Perinatal women were more likely to die from hanging (33.3% [17/51]) or jumping or falling (19.6% [10/51]) than women who died by suicide non-perinatally ( = 0.04). Only 39.2% (20/51) had mental health contact within the 30 days before death, similar to the rate among those who died by suicide non-perinatally (47.7% [762/1597]; odds ratio [OR] 0.71, 95% confidence interval [CI] 0.40-1.25). Compared with living perinatal women matched by pregnancy or postpartum status at date of suicide, perinatal women who died by suicide had similar likelihood of non-mental health primary care and obstetric care before the index date but had a lower likelihood of pediatric contact (64.5% [20/31] v. 88.4% [137/155] at 30 days; OR 0.24, 95% CI 0.10-0.58).INTERPRETATION: The perinatal suicide rate for Ontario during the period 1994-2008 was comparable to international estimates and represents a substantial component of Canadian perinatal mortality. Given that deaths by suicide occur throughout the perinatal period, all health care providers must be collectively vigilant in assessing risk.