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

Abstract

Background: Suicidal 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.

Methods: In 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.

Findings: Data 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]).

Interpretation: We 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.

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

Figure 1.

Unadjusted Incidence Rates of First Suicide Attempt in the Year Before and Year After a First First-trimester Abortion. Panel A: All Women Having an Abortion; Panel B: Women Having an Abortion Stratified by Prior Psychiatric Contact. Panel A. Women having had a first first-trimester abortion (n = 48,990) Panel B. Women having had a first first-trimester abortion stratified by prior psychiatric contact Notes: The period −12 to 0 refers to the period from 12 months before the abortion. І indicates 95% confidence intervals.

Figure 2.

Age and calendar year adjusted Incidence Rate Ratios of First Suicide Attempt Before and After a First First-Trimester Abortion for All Women Who had an Abortion (Panel A), Women Having had an Abortion Who Had a Prior Psychiatric Contact (Panel B), and Women Having had an Abortion Who Did Not Have a Prior Psychiatric (Panel C). Panel A. Women having had a first first-trimester abortion (n = 48,990) Panel B. Women having had a first first-trimester abortion with a prior psychiatric contact (n = 12,080) Panel C. Women having had a first first-trimester abortion without a prior psychiatric contact (n = 36,910) Notes. The horizontal line indicates the reference group of the 11^th and 12th months before the abortion for each group. Error bars indicate 95% Cis. All numbers in Figure 2 are adjusted for age and cohort.

Figure 2.

Age and calendar year adjusted Incidence Rate Ratios of First Suicide Attempt Before and After a First First-Trimester Abortion for All Women Who had an Abortion (Panel A), Women Having had an Abortion Who Had a Prior Psychiatric Contact (Panel B), and Women Having had an Abortion Who Did Not Have a Prior Psychiatric (Panel C). Panel A. Women having had a first first-trimester abortion (n = 48,990) Panel B. Women having had a first first-trimester abortion with a prior psychiatric contact (n = 12,080) Panel C. Women having had a first first-trimester abortion without a prior psychiatric contact (n = 36,910) Notes. The horizontal line indicates the reference group of the 11^th and 12th months before the abortion for each group. Error bars indicate 95% Cis. All numbers in Figure 2 are adjusted for age and cohort.