Munk-Olsen et al

Induced First-Trimester Abortion and Risk of Mental Disorder.  Trine Munk-Olsen, Ph.D., Thomas Munk Laursen, Ph.D., Carsten B. Pedersen, Dr.Med.Sc., Øjvind Lidegaard, Dr.Med.Sc., and Preben Bo Mortensen, Dr.Med.Sc. N Engl J Med 2011;364:332-9.

Abstract

Background
Concern has been expressed about potential harm to women’s mental health in association with having an induced abortion, but it remains unclear whether induced abortion is associated with an increased risk of subsequent psychiatric problems.

Methods
We conducted a population-based cohort study that involved linking information from the Danish Civil Registration system to the Danish Psychiatric Central Register and the Danish National Register of Patients. The information consisted of data for girls and women with no record of mental disorders during the 1995–2007 period who had a first-trimester induced abortion or a first childbirth during that period. We estimated the rates of first-time psychiatric contact (an inpatient admission or outpatient visit) for any type of mental disorder within the 12 months after the abortion or childbirth as compared with the 9-month period preceding the event.

Results
The incidence rates of first psychiatric contact per 1000 person-years among girls and women who had a first abortion were 14.6 (95% confidence interval [CI], 13.7 to 15.6) before abortion and 15.2 (95% CI, 14.4 to 16.1) after abortion. The corresponding rates among girls and women who had a first childbirth were 3.9 (95% CI, 3.7 to 4.2) before delivery and 6.7 (95% CI, 6.4 to 7.0) post partum. The relative risk of a psychiatric contact did not differ significantly after abortion as compared with before abortion (P = 0.19) but did increase after childbirth as compared with before childbirth (P<0.001).

Conclusions
The finding that the incidence rate of psychiatric contact was similar before and after a first-trimester abortion does not support the hypothesis that there is an increased risk of mental disorders after a first-trimester induced abortion. (Funded by the Susan Thompson Buffett Foundation and the Danish Medical Research Council.)

Key Findings

1. Abortion is not associated with any improvement in mental health.  This finding is consistent with previous studies.
   
2. The year following abortion was associated with a higher rate of treatment for some mental health conditions compared to the nine months prior to the abortion, including 1 to 3 months while pregnant. Specifically, relative risk for psychiatric visits involving neurotic, stress-related, or somatoform disorders was 47% and 37% higher for women post-abortion compared to pre-abortion at 2 and 3 months respectively. In addition, psychiatric contact for personality or behavioral disorders was 56%, 45%, 31%, and 55% higher at 3, 4-6, 7-9, and 10-12 months respectively. 
3. The rate of mental health treatments following a first abortion is significantly higher than the rate of mental health treatments following a first delivery. However, the rate of mental health treatment in the nine months prior to abortion (including up to three months coping with pre-abortion stresses) was also higher than the rate of mental health treatments before and after a live birth.
4. Women who have abortions have higher rates of psychiatric treatment (15.2 per 1000 person years) than women who have not been pregnant (8.2 per 1000 person years) and women who deliver their first pregnancy (6.7 per 1000 person years).
5. The findings of this study indicate that compared to other women, the elevated rates of mental health problems associated with abortion occur both before the abortion (during the nine months preceding the date of the abortion) and after the abortion.
6. Because of differences in study design, and because the study did find elevated rates of psychological problems associated with abortion compared to delivering and non-pregnant women, the findings of this study clearly do not contradict previous studies linking abortion to elevated rates of psychological problems. The study does contribute to the literature, however, in that it provides evidence that some mental health problems associated with abortion may arise from pre-abortion stresses, during the time frame of discovering an unintended pregnancy, facing the pressures and concerns associated with making the abortion decision, and undertaking the abortion itself.
7. Clinicians should be alert to the fact that there are higher rates of mental health treatments are sought by women in the year following a first abortion compared to the year following a first delivery.
8. The researchers in this study conclude that the higher rates of mental health treatments provided to women who have abortions is not causally due to abortion, but rather due to a self-selection bias causing women with a propensity to require higher rates of mental health care to be more likely to have abortions.  (This conclusion is a good bit at odds with the study's design since it actually excluded women with a history of inpatient care prior to their first pregnancy, in other words, it was designed to look at the most mentally healthy set of women).  Even if this speculation were confirmed, it raises the interesting question: Is abortion "attractive" to the mentally unstable as an act of healing or as an act of self-destruction?  The lack of any evidence of benefit and the abundance of evidence of continued or increased mental health problems after an abortion suggest that it is not an act of healing.
   
   
   

Limitations

1. The pre-event (abortion or childbirth) measure of mental health was limited to only 9 months.  This period was chosen to include (on average) only the time that a delivering woman was pregnant.  It therefore totally ignores the pre-pregnancy mental health of delivering women. By contrast, for women who had abortions this nine month pre-event window includes six to eight pre-pregnant months plus one to three months during which the woman discovered she was faced with an unintended pregnancy and was deciding on an abortion.  While it is important to control for prior mental health, it would have been far preferable to use the the full life history of psychiatric treatments for women in both groups, or at least a five year history prior to the pregnancy. Such data was available to the researchers.  Why it was not used is unclear.  At the very least, the control period should have been based on a period of time estimated to have been before the women in both groups became pregnant. Furthermore, while the researchers did exclude women who had any prior history of inpatient psychiatric care, they did not control for prior history of outpatient psychiatric care.  In other words, we do not know if there were any differences in the rates of outpatient treatment between the two groups.  Bottom line: the control for prior mental health history in this study is very weak and may even lead to misleading results. To spell out this limitation more fully, this nine-month window on "prior" mental health is problematic for the following reasons.
   • Women who are planning and excited about having a baby may be less likely to seek mental health.  This is why the incidence rate is so low 3.9%.  With only a nine-month pre-event window, the authors are even excluding those women who may have been experiencing anxiety or other problems as they struggled to become pregnant.  So this measure of mental health during a first pregnancy is a poor indicator of mental health prior to a first delivery.
   • Given the lack of more complete controls for mental health history suggested above, we must assume that since both groups had no prior history of outpatient mental health care prior to their first pregnancies, the mental health of both groups was very similar prior to becoming pregnant.  The three fold increase in mental health treatments prior to abortion (14.6 per 1000 yrs) compared to women who gave birth (3.9 per 1000 yrs) would therefore appear to be most likely explained by stress these women faced discovering they were faced with an unplanned pregnancy and, in many cases, the concurrent disruption of relationships with male partners, parents, employers and others.  In addition, abortion women were more likely to involved in unstable and possibly abusive relationships prior to their pregnancies.  It is not surprising, then, that many of these women facing the stress of abortion decision-making sought psychiatric advise at a much more elevated rate than they had in the past.
   • It is a common failure in abortion research to fail to identify the difference between pre-pregnancy mental health and pre-abortion mental health. Proponents of the abortion and mental health (AMH) connection generally support the view that abortion experience includes pre-abortion mental health stressors occur between the impregnation and abortion.  Discovery of the pregnancy, negative interactions with loved ones over the pregnancy, moral struggles, maternal stress, morning sickness, stress related to career and education decisions, and numerous other factors associated with the pregnancy can all contribute to escalating levels of stress.  Indeed, AMH proponents often describe abortion as both a stress reliever (because it resolves some of these pre-abortion stresses) and a stress inducer (because it creates new stresses or calcifies existing stresses).  This study's failure to distinguish between pre-pregnancy mental health history and post-conception/pre-abortion mental health history prevents any application of the findings to the more central question of when, if ever, an abortion to be beneficial.
   • AMH deniers often suggest that higher rates of post-abortion mental health problems, which are consistently found in the literature, are due to higher rates of pre-existing mental health problems unrelated to the abortion or the unintended pregnancy.  This hypothesis has not yet been tested due to the failure to distinguish between pre-pregnancy mental health and pre-abortion mental health.  This study, again, fails to make that distinction, which is especially unfortunate since, being a record based study, the necessary data was available to the researchers. 
     

2. The only confounding variables for which the authors use controls are age and number of pregnancies. Controls for marital status and socioeconomic status are missing, even though such data is generally available in record based studies.
3. All women who had a history of psychiatric inpatient treatment more than 9 months prior to the abortion were excluded from the study. Many studies suggest that these women are at heightened risk for post-abortion mental health problems. Additional research should be done to look only at this subset of women to determine if women with a prior history of significant mental health problems (pre-pregnancy) are likely to have a lower or higher rate of mental health problems after abortion or after childbirth.
4. Women who experience repeat abortions are likewise not considered. Approximately half of all abortions, at least in the United States, are for women with a prior history of abortion. Numerous studies indicate an elevated risk of mental health problems associated with multiple abortions. This study fails to shed any light on this important issue.
5. The limited follow-up to just one year after the pregnancy outcome is also an unfortunate limitation. There is evidence that elevated rates of post-abortion reactions persist for at least four years. Conversely, post-partum reactions tend to occur within the first few months following a delivery and the mental health benefits of childbirth may therefore be underestimated by examining treatment rates within only one year.
6. The study did not examine whether the individual women who had psychiatric treatment prior to the abortion were at higher or lower risk of additional psychiatric treatment after the abortion.  For example, did pre-abortion mental health screening/counseling help to reduce subsequent risk of mental health treatment?  Or was it a predictor of higher rates of subsequent mental health treatment?  This is an important issue not answered by the study.
7. The study excluded women who died (including death from suicide) prior to the end of the 12 month follow-up. Given numerous studies showing higher rates of suicide and deaths from accidents following abortion, this design decision may skew the results.
8. The study considered only a single psychiatric treatment.  It did not measure or weight repeated treatments, which might be used as a measure of the severity and duration of mental health problems.
9. The authors' conclusions are not consistent with the data. Specifically, the authors conclude: "our study shows that the rates of a first-time psychiatric contact before and after a first-trimester induced abortion are similar."  The identification of some "similar" rates, however, does not mitigate the fact that their data also shows several statistically significant higher rates for specific mental disorders following abortion (see table 1).  Additional study, and better controls, may reveal even more significant differences.  In addition, the authors statement that "This finding does not support the hypothesis that there is an overall increased risk of mental disorders after first-trimester induced abortion," oversimplifies and misrepresents the hypotheses presented by AMH proponents.  Even more importantly, the findings of this study do not contradict even this oversimplified hypothesis.  Instead, the conclusion seems crafted to be a sound-bite that obfuscates rather than clarifies the issues of concern.
10.  The study put women in both categories.  Women who had both an abortion and delivery appeared in both groups.  This may have confounding effects.  To eliminate these confounding effects the authors should have limited the study to first pregnancy outcome, and included miscarriage and other natural losses as a third group.
11. Curiously they did not follow the research approach used in previous Danish Study Hospitalization for Mental Illness among Parents after the Death of a Child which examined mental health over a much longer period than just 12 months.