The association between first abortion and first-time non-fatal suicide attempt: a longitudinal cohort study of Danish population registries.

backgroundSuicidal ideation due to abortion has been used to justify restrictive US abortion policies. Much research examining abortion and mental health has relied on self-report, has had low participation rates, and did not consider confounding factors. In the present study, we used data that do not rely on self-report and are not affected by low participation rates to examine the association between abortion and non-fatal suicide attempts, adjusting for confounding factors.

methodsIn this longitudinal cohort study of Danish population registries, we linked data on a cohort of women born in Denmark between Jan 1, 1980, and Dec 30, 1998, who did not die or emigrate from Denmark before their 18th birthday or before study entry. Follow-up started on the woman's 18th birthday or Jan 1, 2000, whichever came last. Follow-up ended at the date of first suicide attempt, date of emigration from Denmark, date of death, or Dec 31, 2016, whichever came first. Women were between the ages of 18 and 36 years during the study period. We used a survival analysis to examine the risk of first suicide attempts or self-harm associated with a first abortion compared with no abortion, in the complete study cohort. To examine incidence rate ratios (IRRs) associated with abortion, we used Poisson regression with the logarithm of woman-years at risk as an offset. We also examined whether the risk of suicide attempts changed before and after the abortion, adjusting for age, calendar year, socioeconomic status, and history of childbirth, mental health, parental mental health, and physical health.

findingsData on 523 280 women were included in this study. Of these, 48 990 (9·4%) women had a record of at least one first-trimester abortion, and 10 216 (2·0%) had a suicide attempt during the study period. Among 48 990 women who had an abortion, 1402 (2·9%) had a first suicide attempt after the first abortion. In our fully-adjusted model which adjusted for all covariates, the risk of first-time non-fatal suicide attempts was similar in the year before an abortion (IRR 2·46 [95% CI 2·22-2·72]) and the year after an abortion (IRR 2·54 [2·29-2·81], p=0·509) compared with women who had not had an abortion, and decreased with increasing time since the abortion (1-5 years IRR 1·90 [1·75-2·06]; ≥5 years IRR 1·73 [1·53-1·96]).

interpretationWe found that women who had abortions had a higher risk of non-fatal suicide attempts compared with women who did not have an abortion. However, because the increased risk was the same both the year before and after the abortion, it is not attributable to the abortion. Thus, policies based on the notion that abortion increases women's risk of suicide attempts are misinformed.

fundingSociety of Family Planning, American Foundation for Suicide Prevention, and The Lundbeck Foundation Initiative for Integrative Psychiatric Research.