Objective: To examine the links between pregnancy outcomes (birth, abortion, or involuntary pregnancy loss) and mental health outcomes for US women during the transition into adulthood to determine the extent of increased risk, if any, associated with exposure to induced abortion.
Method: Panel data on pregnancy history and mental health history for a nationally representative cohort of 8005 women at (average) ages 15, 22, and 28 years from the National Longitudinal Study of Adolescent to Adult Health were examined for risk of depression, anxiety, suicidal ideation, alcohol abuse, drug abuse, cannabis abuse, and nicotine dependence by pregnancy outcome (birth, abortion, and involuntary pregnancy loss). Risk ratios were estimated for time-dynamic outcomes from population-averaged longitudinal logistic and Poisson regression models.
Results: After extensive adjustment for confounding, other pregnancy outcomes, and sociodemographic differences, abortion was consistently associated with increased risk of mental health disorder. Overall risk was elevated 45% (risk ratio, 1.45; 95% confidence interval, 1.30-1.62; p < 0.0001). Risk of mental health disorder with pregnancy loss was mixed, but also elevated 24% (risk ratio, 1.24; 95% confidence interval, 1.13-1.37; p < 0.0001) overall. Birth was weakly associated with reduced mental disorders. One-eleventh (8.7%; 95% confidence interval, 6.0-11.3) of the prevalence of mental disorders examined over the period were attributable to abortion.
Conclusion: Evidence from the United States confirms previous findings from Norway and New Zealand that, unlike other pregnancy outcomes, abortion is consistently associated with a moderate increase in risk of mental health disorders during late adolescence and early adulthood.
Keywords: Abortion; longitudinal data; mental health; pregnancy outcomes; substance abuse.