Induced abortion is a prevalent response to an unintended pregnancy. The long-term health consequences are poorly investigated and conclusions must be drawn from observational studies. Using strict inclusion criteria (study population >100 subjects, follow up >60 days) we reviewed an array of conditions in women’s health. Induced abortion was not associated with changes in the prevalence of subsequent subfertility, spontaneous abortion, or ectopic pregnancy. Previous abortion was a risk factor for placenta previa. Moreover, induced abortion increased the risks for both a subsequent preterm delivery and mood disorders substantial enough to provoke attempts of self-harm. Preterm delivery and depression are important conditions in women’s health and avoidance of induced abortion has potential as a strategy to reduce their prevalence. Only review articles including the single published meta-analysis exploring linkages between abortion and breast cancer were relied upon to draw conclusions. Reviewers were mixed on whether subsequent breast neoplasia can be linked to induced abortion, although the sole meta-analysis found a summary odds ratio of 1.2. Whatever the effect of induced abortion on breast cancer risk, a young woman with an unintended pregnancy clearly sacrifices the protective effect of a term delivery should she decide to abort and delay childbearing. That increase in risk can be quantified using the Gail Model. Thus, we conclude that informed consent before induced abortion should include information about the subsequent risk of preterm delivery and depression. Although it remains uncertain whether elective abortion increases subsequent breast cancer, it is clear that a decision to abort and delay pregnancy culminates in a loss of protection with the net effect being an increased risk.
Target Audience: Obstetricians & Gynecologists, Family Physicians
Learning Objectives: After completion of this article, the reader will be able to define the terms abortion rate and abortion ratio, to outline the epidemiologic problems in studying the long-term consequences of abortion, and to list the associated long-term consequences of abortion.
In the late 1960s and early 1970s, abortion was legalized in most of the western world. Legalization culminated in more women choosing termination than had been expected (1,2), with young, socially deprived, and childless women making up the largest proportion (3). Initially, research focused on early complications, immediate maternal mortality, and optimization of abortion technique (4). Subsequent interest in the potential long-term health consequences entered scientific discussion later, not primarily driven by specific hypotheses, but rather by those with conflicting viewpoints, vis a vis, the moral status of the embryo or fetus, and the desire to either limit or expand access to abortion (5). As profound sociologic changes in reproductive behavior were documented in the form of rising abortion rates, political pressures motivated governments to appoint special study commissions charged with the task of reporting on the long-term health implications of induced abortion (6,7). The resulting reports lament the lack of long-term follow-up and call for detailed study of the health effects of this common procedure. Despite strong recommendations for substantive research, and the clear need for women to have accurate information as they execute their autonomy, current data remain sparse, studies are small and methodologically flawed, and the conclusions are often intertwined with the political agendas of their authors and publishers (8).
*Mcallister Distinguished Professor of Obstetrics and Gynecology, † Assistant Professor, Department of Epidemiology,School of Public Health, and Department of Obstetrics and Gynecology, School of Medicine, Chapel Hill, North Carolina and ‡ Associate Professor, Department of Obstetrics & Gynecology, School of Medicine, University of Michigan, Ann Arbor, Michigan
Reprint requests to: John M. Thorp, Jr, MD, Department of Epidemiology, School of Public Health, University of North Carolina, Department of Obstetrics and Gynecology, School of Medicine, Chapel Hill, NC 27599. Email: JMT@med.unc.edu.
The authors have disclosed no significant financial or other relationship with any commercial entity.