The incidence of breast cancer among women has certainly risen alarmingly in the past three decades. Many explanations for this rise have been suggested: a more polluted environment, changes in diet, smoking, the postponement of childbearing, the contraceptive pill, and other drug therapies.

But the media have paid almost no attention to the many studies that have documented a significantly higher incidence of breast cancer among women who have abortions, in particular those who abort their first pregnancy before the age of 20. At least 27 studies in ten countries have discovered an increased risk of 30 per cent-significantly higher than the increased risk of 25 per cent reported in the single study of the effects of HRT.

Strange to say, the authors and sponsors of several of these studies have shied away from the implications of their findings. The National Cancer Institute in the U.S., for example, sponsored a major study which showed a 36 per cent increased risk (rising to a disturbing 50 per cent among women under 20 who abort their first pregnancy) of breast cancer among women who undergo abortions. In fact, given that young women who carry their first pregnancy to term reduce their chances of breast cancer by 30 per cent, the consequences are even more dramatic. The lifetime chances of a woman in North America being diagnosed with breast cancer are currently about ten per cent. A woman who has a child before age 20 has a seven per cent chance. On the other hand, if she aborts that first early pregnancy, she more than doubles her lifetime chances to fifteen per cent. Yet the National Cancer Institute, and other establishment voices such as the prestigious New England Journal of Medicine stoutly continue to deny that there is any link between abortion and breast cancer.

Curiously, the establishment on the other side of the ocean is much less reluctant to recognize the link. In April 2000, Britain’s Royal College of Obstetricians and Gynecologists acknowledged that studies demonstrating the abortion-breast cancer link “could not be disregarded.”1 Writing in the London Times a year later, Dr. Thomas Stuttaford declared that “an unusually high proportion” of the women diagnosed with breast cancer in the U.K. each year “had an abortion before eventually starting a family. Such women are up to four times more likely to develop breast cancer.”2

There are solid physiological reasons for the association between induced abortion and the later development of breast cancer which have to do with the hormonal effects of pregnancy on a woman’s breast tissue. A surge of the hormone oestradiol at conception reaches twentyfold in the first trimester, triggering an explosive growth of breast tissue-a period when breast cells are most likely to be affected by carcinogens. When a woman completes her first full pregnancy, further hormonal changes propel these newly produced breast cells through a state of differentiation, a natural maturing process that greatly reduces the risk of future breast cancer.3 An early, abrupt termination of pregnancy by abortion arrests this process before the cancer-reducing evolution of hormone release can occur, leaving a large population of dangerously-stimulated breast tissue cells in place, enormously raising future cancer risk. On the other hand, “. . . an early first, full-term pregnancy would provide the greatest protection against breast cancer by drastically reducing, early on, the presence of undifferentiated and hence vulnerable breast cells, thereby decreasing the risk of subsequent transformation.”4 A fascinating animal study supports this line of reasoning. Two groups of rats were exposed to a chemical carcinogen before mating. The group that carried a first pregnancy to term developed mammary tumours at a rate of six per cent. The group whose pregnancies were aborted, however, developed mammary tumours at an astounding rate of 78 per cent.5

These are among several dramatic findings dredged up from the obscurity of scientific journals and presented in Women’s Health After Abortion: The Medical and Scientific Evidence, a new book I co-authored with Elizabeth Ring-Cassidy.6 In it, we review and summarize over 500 studies which have appeared in medical and professional journals, most of them over the past twenty years. What follows here is a brief overview of our work.

Cancers of the cervix, ovaries and rectum
Research in this area is in its early stages, but a few studies from the past decade point to a link between abortion and subsequent cancers of the reproductive system, as well as colorectal cancer. Cervical cancer in particular seems to be directly associated with induced abortion. Studies of cancer of the ovary have presented conflicting evidence. A strong association has been discovered between abortion and cancer of the rectum. What is remarkable is that with the increase in cancers of the breast and reproductive system in women over the past thirty years, there has as yet been so little interest in investigating the link with induced abortion. Despite the overwhelming weight of the studies pointing to such a link, their conclusions have been generally ignored by the research establishments in North America. The rationale for this may be that for some it is more important for abortion to remain accessible than for women to be informed about a clear threat to their health. Thus, the politicized and controversial nature of the subject, and the desire of some powerful groups to keep abortion “safe, simple, and easily available,” have militated against the objective consideration of data pointing strongly to a link between abortion and various cancers.

Maternal mortality
In both Canada and the U.S. there is a general and systematic underreporting of maternal deaths, whether from abortion, pregnancy, or during delivery. Not least among the reasons for this is the fact that more and more abortions are now performed in free-standing clinics. A woman whose post-abortion condition is life threatening generally goes to a hospital, not back to the clinic. The attending emergency room doctor may not record a subsequent death as resulting from an abortion. The practice of coding the immediate rather than the underlying cause of death also causes underreporting: an induced abortion may result in bleeding, embolism, cardiac arrest or infection, or it may lead to a subsequent ectopic pregnancy. But the death certificate of a woman who dies from these conditions may make no reference to abortion.

A recent, large-scale Scandinavian study found that within one year of the end of a pregnancy, women who had induced abortions suffered a mortality rate that was almost four times greater than that for women who delivered their babies. And their rate of suicide was six times greater.7 A recent study in Wales found that women who had induced abortions were 2.25 times more likely to commit suicide than women admitted for normal delivery.8 A large-scale California study just recently published reported similar findings. These studies, using record linkage and involving many hundreds of thousands of cases, authoritatively refute the oft-repeated fiction that induced abortion is safer for women than giving birth.

Ectopic pregnancy
While overall health has generally improved in the past century, there has been a disturbing rise in ectopic pregnancies. Between 1970 and 1990 they doubled, trebled or quadrupled in frequency, depending on the country, so that they now account for two per cent of all pregnancies in the areas studied. The rise of ectopic pregnancy coincides almost exactly with the steep rise in the frequency of induced abortion during the same period. Studies from Italy, Japan, Yugoslavia and the U.S. have documented a much higher risk of ectopic pregnancy among women who have had one or more abortions. Yet the authors of an American study that uncovered a 160 per cent increased risk arrived at the strange conclusion that abortion “does not carry a large excess risk” of ectopic pregnancy.9 This is one of many examples in the literature of abortion researchers making statements in the abstracts or conclusions of their articles that flatly contradict their findings.

Uterine perforations, pelvic inflammatory disease, and infertility are among the other risks involved in surgical abortion are uterine perforation, uterine adhesions, retained fetal fragments and infections that lead to pelvic inflammatory disease (PID). PID is now epidemic in Canada and much of the rest of the world. Nearly 100,000 women contract it each year in Canada alone. The disease is difficult and expensive to treat, and causes infertility in women. The link between PID and abortion is well established in the sense that women who undergo surgical abortions suffer a much higher incidence of PID afterwards. The link is even stronger among women who have had two or more abortions.10

Pain and abortion
Some abortion clinics attempt to reassure their patients that the pain they are about to suffer will resemble nothing greater than heavy menstrual cramps. A large study conducted in Montreal paints a different picture. Pain is the most subjective of experiences, yet when the pain scores of these abortion patients were checked against other acute and chronic pain syndromes, “they were found to be higher than fractures, sprains, neuralgia or arthritis, and equal to those of amputees experiencing phantom limb pain and patients with cancer.” When it comes to mental pain, abortion is often touted as bringing relief from the depression caused by pregnancy. Not necessarily so. The Montreal study found that 50 per cent of the women who had high depression scores “remained clinically depressed and anxious two weeks after the procedure.”11 

Chemical Abortions

Chemical or drug-induced abortions have been hailed in some quarters as a less traumatic solution to an unwanted pregnancy than surgical abortion. Yet these are not without their own difficulties. A variety of studies have found failure rates ranging from 6 to 45 per cent, necessitating a second, surgical abortion. There are unpleasant side effects, including prolonged bleeding, diarrhea, fevers and nausea, as well as the inconvenience of several visits to the doctor and the lack of immediate confirmation of the success of the procedure. Typically, the abortion is not triggered until twenty-four days after the drug has been administered. Furthermore, the pain is reported to be even greater than surgical abortion.12

Risks to future children
image-066The most recent studies point to an approximately 85 per cent increase in premature (or “very preterm,” meaning less than 33 weeks’ gestation) births to women who have had a previous induced abortion. This risk increases sharply with every additional abortion that a woman undergoes.13 Premature infants suffer a very high incidence of disability. Their rate of cerebral palsy for example, is thirty-eight times greater than that of the general population. Induced abortion, therefore, has appalling implications for women who subsequently wish to bear a child. It is the direct cause of many thousands more cases of cerebral palsy in North America than otherwise would have occurred.

Depression, guilt and low self-esteem
Abortion is frequently touted as the obvious answer to a woman’s emotional distress at the discovery that she is pregnant. Research suggests that this is a glib answer. Far from being a “quick fix,” abortion exacerbates problems such as depression, grief or low self-esteem. In general, women who are suffering from psychological or psychiatric disorders before they undergo an abortion will continue to experience these difficulties afterwards, sometimes in greater measure.14 A very large-scale study in California, using record linkage, found that over a four-year period women who aborted had a 72 per cent higher rate of psychiatric admission to hospital than women who delivered their babies.15

Repeat abortions are a growing phenomenon in both Canada and the U.S., where they constitute forty and fifty per cent respectively of all abortions. Women who undergo the experience of two or more abortions also experience lowered self-esteem coupled with a lack of self-respect. In the words of one researcher, “rather than being a relief, an abortion may be additional proof of their worthlessness.”16

Many women have mixed feelings about their decision to abort. It has been shown that ambivalence about having an abortion entails a greater likelihood of suffering negative emotional consequences such as depression and guilt. Ambivalent women more often state that it was their partner who decided on the abortion. Only a minority initially wanted it. The discovery that many women are pressured into abortion by men is not surprising if we bear in mind that opinion surveys have consistently found more women opposing abortion than men. This is because abortion often suits men’s convenience much better than it does women’s.


Teenagers who abort are at greater risk than older women for later psychological and physical problems. They suffer lower self-esteem, absence of affect and greater symptoms of depression than those who are either not pregnant or carry their pregnancies to term. The most striking evidence of this is a major American study which found a six to tenfold increase in suicide attempts among adolescent girls who had had an abortion at any time in their lives.17

The higher suicide rate also applies, though less dramatically, to older women. The high rate of post-abortion suicide has never been taken into account by those who claim that abortion is a safer procedure than childbirth.

Religion and healing
Women who are religious are very likely to experience regret or guilt after abortion. The simplistic solution sometimes offered is that women should abandon their religion or switch to one that doesn’t induce guilt. Either that, or the major religions that frown on abortion-Judaism, Islam, Christianity-should change their positions. In contrast to this advice, it has been found that some of the most interesting efforts to promote women’s emotional healing after abortion involve the harnessing of their religious spirituality. Initiatives such as Project Rachel put forgiveness at the heart of their therapy: forgiveness of everyone involved in the woman’s abortion, forgiveness of herself, and finally, discernment of how to move on and make a positive impact on her world.18

Grief therapy and abortion for genetic reasons an increasing number of pregnancies are aborted because prenatal tests have shown the fetus to be defective in some way. Interestingly, there is no attempt to deny or minimize the distress and grief that often accompany these types of abortion. The loss of a defective fetus is recognized as being equivalent to the loss of a child. This legitimizes the use of humanizing terms. It is permissible to grieve. Researchers drop the word “fetus” and write instead about “the baby’s abnormality,” the “death of the baby,” “guilt over having killed the baby,” “saw the child,” “lost baby,” and so on. Why this starkly different approach? Apparently it is because a pregnancy aborted for genetic reasons is assumed to be, in the beginning at least, a wanted pregnancy. Yet it is known that depressive symptoms following pregnancy loss are unrelated to the woman’s attitude towards the pregnancy. In other words, the woman who rejects her pregnancy is just as likely to grieve her loss as the woman who wanted to be pregnant.19

The effect on siblings
Almost never considered in the abortion decision is its impact on other children in a family. Children do not understand the socially-constructed distinction between fetus and baby. If they find out about their parents’ decision to abort a pregnancy, they undergo marked and disturbing reactions. “Abortion can produce a deep, subtle (and often permanent) fracture of the trusting relationship that once existed between a child and parent.”20 Furthermore, the knowledge that a potential sibling has been aborted can lead to behavioral disturbances, emotional insecurity, fears of abandonment, and delayed grief that surfaces years later.

Men are generally more favorable to abortion than women. Yet the stark fact is that men have no rights whatever when it comes to abortion. Their only options are to support the woman emotionally if she aborts, or support her financially if she chooses to bear the child. Thus for men abortion can be “a private exercise in powerlessness.” Many experience grief at the loss of the child they have fathered, and may have a psychological need for recognition of their mourning. This could also be a reason why so many men abandon the relationship after an abortion.

Interpersonal relationships

There is no doubt that abortion results in worsening relationships between women and those who are close to them. The rate of marital breakup and relationship dissolution is anywhere from 40 to 75 per cent after abortion. Couples commonly experience reduced libido. A previous abortion leads to more post-partum depression following a subsequent delivery. There is less bonding, less touching and less breast-feeding of the new baby. More than one study has found that women who abort are also likelier to abuse their other children. Conversely, people who have been abused are more likely to have an abortion. Far from ending the problem of child abuse, abortion appears to have made it worse.22

Much post-abortion research is conducted by those committed to preserving unrestricted access to induced abortion. Their tendency is to cite only the work of those who share their political outlook on the question. Most post-abortion research is short-term, with the result that long-term consequences tend to be ignored. Many women, especially those who abort late in pregnancy, are unwilling to participate in follow-up studies. Finally, in North America, unlike in European and other countries, there is a pronounced bias against reporting bad news about induced abortion.

In a surprising number of North American studies data on abortion are downplayed or omitted from the discussion or conclusion sections of the paper. Here are a few examples from the highly contentious field of breast cancer and abortion. In 1995 Lipworth and colleagues found that there was a 100 per cent increased risk of breast cancer for women whose first pregnancy ended in abortion. In the discussion section the author downplayed this increase as “at most statistically marginal.”23 In another study Ewertz and Duffy found that induced abortions were associated with an almost fourfold increased risk of breast cancer. In the discussion section this finding was not commented upon, the authors confining themselves to the observation that “pregnancies must go to term to exert a protective effect against breast cancer.”24 A study by Daling and colleagues found a 2.5 risk-in other words a 150 per cent increase in the risk of breast cancer for women whose first pregnancy was aborted before age eighteen-but in their Discussion Section said that their findings “give only slight support to the hypothesis that there is an increase in breast cancer incidence among women of reproductive age.”25

The investigation of abortion’s after-effects is also bedeviled by coding and diagnostic problems. International Disease Classification codes prevent cross-referencing between ectopic pregnancy and induced abortion, even though a clear link has been demonstrated. Pelvic inflammatory disease or Asherman’s Syndrome (intra-uterine adhesions, a complication of surgical curettage) may arise from an abortion but not be identified in that way either.

All the adverse effects of abortion put together affect perhaps twenty per cent of the women who undergo the procedure. Though a minority, they are a substantial one. The question that Women’s Health After Abortion raises is: Are women entitled to know about the risks? Or are those who draw attention to them merely sowing unnecessary despondency and alarm, as some would claim? Fortunately the courts have already established that informed consent must be an essential ingredient of good patient care. Elective procedures-and induced abortion is an elective procedure-require from the physician a greater degree of disclosure than emergency procedures. Common but minor risks must be disclosed. Extremely rare risks must also be disclosed if they have serious or fatal consequences.

I co-authored this study because of a conviction that the increased risks associated with induced abortion-breast cancer, death, sterility, ectopic pregnancy, pelvic inflammatory disease, emotional distress, harm to subsequent children, the impact on partners and other children-are serious enough to merit dissemination beyond the pages of professional journals. If women have the right to choose, surely they also have the right to make their choice an informed one.

1. Royal College of Obstetricians and Gynaecologists. Evidence-based Guideline no. 7: The Care of Women Requesting Induced Abortion. (London, Apr. 2000).
2. The Times (17 May 2001), p. 8.
3. J.L. Kelsey, “A review of the epidemiology of human breast cancer.” Epidemiologic Reviews. 1979; 1:74-109.
4. N. Krieger. “Exposure, susceptibility, and breast cancer risk.” Breast Cancer Research and Treatment 1989 July (13:3), 205-223.
5. J. and I.H. Russo. “Susceptibility of the mammary gland to carcinogenisis. II. Pregnancy interruption as a risk factor in tumor incidence.” American Journal of Pathology 1980; 100 (2): 497-512.
6. Elizabeth Ring-Cassidy and Ian Gentles. Women’s Health after Abortion: The Medical and Psychological Evidence. Toronto: de Veber Institute for Bioethics and Social Research, 2002.
7. M. Gissler et al. “Suicides after Pregnancy in Finland, 1987-94: Register Linkage Study.” British Medical Journal 1996 Dec. 7; 313(7070): 1431-4; M. Gissler et al. “Pregnancy-Associated Deaths in Finland, 1987-94-Definition Problems and Benefits of Record Linkage.” Acta Obstetricia et Gynecologica Scandanavica 1997 August; 76(7): 651-7.
8. C.L. Morgan et al. “Suicides after pregnancy. Mental health may deteriorate as a direct effect of induced abortion.” British Medical Journal 1997 March 22; 314 (7084); 902-3.9. J.R. Daling et al. “Ectopic pregnancy in relation to previous induced abortion.” Journal of the American Medical Association 1985 February; 253 (7) 1005-8.
10. J.L. Sorenson et al. “A double-blind randomized study of the effect of erythromycin in preventing pelvic inflammatory disease after first-trimester abortion.” British Journal of Obstetrics and Gynaecology 1992 May; 99(5): 436.
11. E. Belanger et al. “Pain of the first trimester abortion: a study of psychosocial and medical predictors.” Pain 1989 March; 36(3): 339-50.
12. M.D. Crenin. “Methotrexate for abortion at 
13. P.V. Ancel. “Very and moderate preterm births: are the risk factors different?” British Journal of Obstetrics and Gynaecology 1999 Nov.; 106(11):1162-70.
14. J.A. Rosenfeld. “Emotional responses to therapeutic abortion.” American Family Physician 1992 January; 45(1): 137.15. J.R. Cougle et al. “Psychiatric admissions following abortion and childbirth: A record-based study of low-income women.” Archives of Women’s Mental Health 2001; 3(4) Supp. 2:47.
16. M. Gissler et al. “Suicides after pregnancy-authors’ reply.” British Medical Journal 1997 March 22; 314(7084):902-3.
17. B. Garfinkel et al. “Stress, depression and suicide: a study of adolescents in Minnesota.” In Responding to High Risk Youth. Minnesota Extension Service, University of Minnesota (1986). 43-55.
18. V. Thorn. “Project Rachel: Faith in action, a ministry of compassion and caring.” In Post-Abortion Aftermath, ed. M. Mannion. Kansas City, MO: Sheed and Ward, 1994: 144-63.
19. D.C. Reardon et al. “Depression and unintended pregnancy in the National Longitudinal Survey of Youth: a cohort study.” British Medical Journal 2002 January 19; 324(7330): 151-2.
20. J. Carton, J. “The cultural impact of abortion and its implications for a future society.” In M. Mannion, ed. Post-Abortion Aftermath. Kansas City: Sheed and Ward, 1994: 91.
21. Rue, V. “The psychological realities of induced abortion.” In M. Mannion, ed. Post-Abortion Aftermath. Kansas City: Sheed and Ward, 1994, p. 24.
22. P. Ney, P. “Relationship between abortion and child abuse.” Canadian Journal of Psychiatry 1993 October; 24(7): 610-20; M.I. Benedict et al. “Maternal perinatal risk factors and child abuse.” Child Abuse and Neglect 1985; 9(2): 217-24.
23. L. Lipworth et al. “Abortion and the risk of breast cancer: a case-control study in Greece.” International Journal of Cancer 1995 April; 61(2): 184.
24. M. Ewertz et al. “Risk of breast cancer in relation to reproductive factors in Denmark.” British Journal of Cancer 1988 July; 58(1): 102.
25. J.R. Dating et al. “Risk of breast cancer among white women following induced abortion.” American Journal of Epidemiology 1996 August; 144(4): 379.
Ian Gentles is research director of the deVeber Institute, and Professor of History at York University, where he teaches a seminar on human population and the family.

First published, research sponsored by the deVeber Institute for Bioethics. Reprinted with permission.