Undergoing a first-trimester induced abortion does not raise the risk of readmission among women with a history of psychiatric hospitalization, according to a report in the February issue of the Archives of General Psychiatry.
It appears that induced first-trimester abortion doesn’t influence the disease course of any mental disorder, said Trine Munk-Olsen, Ph.D., of the National Centre for Register-Based Research, University of Aarhus (Denmark), and her associates.
Previous studies examining induced abortions’ adverse affects on mental health have produced conflicting results and have been flawed by low response rates (resulting in highly selected patient populations), high attrition rates, recall bias, and imprecise measures of both the abortion procedures and mental disorders.
To circumvent these problems, Dr. Munk-Olsen and her colleagues analyzed detailed data from Danish national registeries of all psychiatric admissions for any type of mental disorders and all induced abortions between 1994 and 2007 among women born during 1962-1992. For a comparison group, they assessed all live births in that same study period among women of the same ages with a history of psychiatric admissions for any type of mental disorder.
The researchers identified 2,838 women who had records of mental disorders and who underwent a first-time, first-trimester induced abortion in the study period. A total of 321 of these women had a psychiatric readmission during the interval from 9 months preceding to 12 months after the procedure.
In comparison, 5,293 women with records of mental disorders gave birth to a first child in the same study period. A total of 273 of these women had a psychiatric readmission during the interval from 9 months preceding to 12 months after the birth.
The crude incidence rates of psychiatric readmission declined during the interval from before the abortion to after the induced abortion. In contrast, the crude incidence rates of psychiatric readmission increased during the interval from before the childbirth to after the birth, the investigators said (Arch. Gen. Psychiatry 2012;69:159-65).
In addition, the risk of psychiatric readmission was higher at 1 month after childbirth than it was at 1 month after induced abortion.
The risks of psychiatric readmission around the time of undergoing an abortion were not significantly elevated at any particular time point or for any diagnostic category of mental disorder. In contrast, the risk of psychiatric readmission around the time of childbirth was significantly elevated during the first postpartum month and in the diagnostic categories of bipolar affective disorders and schizophrenialike disorders.
The researchers concluded that "the decision to undergo [an] induced abortion did not appear to influence the subsequent illness course in our study population."
Two prognostic factors were found to be strong predictors of readmission for all the study subjects: a shorter interval since the last psychiatric admission and a higher number of previous admissions. Therefore, previous studies that assessed the risk of readmission but failed to control for the proximity of the last hospitalization and the number of previous hospitalizations likely produced inaccurate results, Dr. Munk-Olsen and her associates said.
Although the registries collected much more accurate data than could be obtained by self-report, one limitation of this study is the lack of information on whether the pregnancies were wanted or unwanted or reasons for the abortion, they added.
This study was sponsored by the Susan Thompson Buffett Foundation and the Danish Medical Research Council. Dr. Munk-Olsen’s associates reported ties to Bayer Schering Pharma and the Stanley Medical Research Institute.