Prenatal Origins of Suicide Mortality: A Prospective Cohort Study in the United States

Aims: Most suicide research focus on acute precipitants and is conducted in high-risk populations. Yet, vulnerability to suicide is likely established years prior to its occurrence. In this study, we aimed to investigate the risk of suicide mortality conferred by prenatal sociodemographic and pregnancy-related factors. Methods: Offspring of participants (N=49,853) of the Collaborative Perinatal Project, a U.S. population-based cohort of pregnancies enrolled between 1959 and 1966, were linked to the U.S. National Death Index to determine their vital status by the end 2016. We examined associations between sociodemographic factors during pregnancy, pregnancy complications, labor and delivery complications, and neonatal complications with suicide death coded according to ICD-9/10 criteria. Results: By the end of 2016, 3,555 participants had died. Of these, 288 (214 males, 74 females) died by suicide (incidence rate=15.6 per 100,000 person-years, 95% Confidence Interval [CI]=13.9-17.5). In adjusted models, male sex (Hazard Ratio [HR]=2.98, CI: 2.26-3.93), White race (HR=2.14, CI=1.63-2.83), low parental education (HR=2.23, CI=1.38-3.62), manual parental occupation (HR=1.38, CI=1.05-1.82), being a younger sibling (HR=1.52, CI=1.10-2.11), higher rates of pregnancy complications (HR=2.36, CI=1.08-5.16), and smoking during pregnancy (HR=1,28, CI=0.99-1.66) were independently associated with suicide risk, whereas birth and neonatal complications were not. Conclusions: Consistent with the developmental origins of psychiatric disorders, vulnerability to suicide mortality is established early in development. Both sociodemographic and pregnancy factors play a role in this risk, which underscores the importance of considering life course approaches to suicide prevention, possibly including provision of high-quality prenatal care, and alleviating the socioeconomic burdens of mothers and families.