Religious Tolerance logo

Abortion and medical problems

Do abortions cause miscarriages later in life?

horizontal rule

Sponsored link.

horizontal rule

What causes miscarriages?

Anthony R. Scialli of the Department of Obstetrics and Gynecology at Georgetown University Medical Center states that "Most doctors consider a miscarriage as a protective mechanism that prevents the continued pregnancy of a nonviable or abnormal embryo or fetus." 1 The apparent incidence of miscarriage has increased over the past 2 decades with the development of more sensitive pregnancy tests. In the past, women may not have noticed many miscarriages. Currently, with home tests capable of detecting pregnancy as soon as 2 days before a missed period, more women have become aware of being pregnant and subsequently having a miscarriage. Dr. Scialli quotes recent studies which indicate that about 31% of pregnancies end in miscarriage. This rises to over 50% for women over 40 years of age.

Causes of miscarriage include:

bullet Genetic defects: Most embryos or fetuses that miscarry have been conceived with an abnormal number of chromosomes. Others have the correct number of chromosomes but involve an abnormal gene.

bullet Immune system: Since the embryo contains foreign genetic material, it can trigger the woman's immune system, which treats it a foreign substance. A blocking mechanism normally acts to inhibit the immune system during pregnancy. However, it can fail. In some cases, a woman's immune system will attack the placenta, even though it is made up of the woman's cells.

bullet Hormones: Too low a level of the hormone progesterone can cause a miscarriage.

bullet State of the uterus: A miscarriage may be caused by the uterus having an abnormal shape, or adhesions due to previous surgeries.

bullet Infections: Some bacteria (listeria, chlamydia) and some viruses (herpes simplex, cytomegalovirus) can cause a miscarriage.

bullet Radiation exposure: High levels of radiation (as used in treating uterine cancer) usually induces a miscarriage in early pregnancies. According to a number of Internet sources, lower levels, as in diagnostic x-rays do, "...not increase the risk of miscarriage."

bullet Lifestyle factors: The consumption of alcohol and smoking have been associated with higher chances of miscarriage. In 1980, the U.S. Food and Drug Administration issued a warning against the use of caffeine by pregnant women. Animal studies had "linked caffeine to increased rates of birth defects, low birth weight, stillbirths and miscarriage" in animals. A more recent study found that even decaffeinated coffee influenced the miscarriage rate. It "found that women who drank three or more cups of decaffeinated coffee a day in the first trimester had 2.4 times the risk of miscarriage as those who did not drink decaf." 2

bullet Medication: Specific drugs have been linked to increased chance of miscarriage.

horizontal rule

Can abortions cause miscarriages?

It would seem that having a surgical abortion could scar a small section of the wall of the uterus and thus increase the chance of a subsequent miscarriage. The remaining potential causes of miscarriages listed above appear to be unrelated to any prior abortion.

Eventually, almost all surgical abortions will probably be phased out, and replaced with:

bullet Emergency contraception (a.k.a. the morning-after pill) taken shortly after unprotected sex, or
bullet Non-surgical, medically induced abortions, or
bullet Manual vacuum aspiration, or the
bullet RU-486 abortion pill.

These do not cause significant uterine wall damage. The chance of any increased miscarriage rates should be eliminated.

horizontal rule

Sponsored link:

horizontal rule

How great is the increased risk of miscarriage after an abortion?

A series of 5 studies have been quoted by pro-life groups and published in numerous web sites, scattered throughout the Internet. 3,4

bullet Levine et al.: This study was confined to "aggressively done abortions," and is thus not representative of typical surgical abortions. They found no increase in late abortions as a result of a single abortion. However, they found a 2 to 3 times increase risk of first trimester miscarriages after two or more abortions. 5

bullet Hilgers et al.: This describes a long term study on 52 women who had had an abortion. Their their subsequent pregnancies were followed. Unfortunately, the study is of little value because they did not include a control group of women who had not had abortion. They did report a 27% miscarriage rate which is lower than average. 6

bullet Kodasek: This is a 1971 Czechoslovakian study. It refers to "cervical incompetence" causing the incidence of miscarriages to reach 30 to 40%. This would represent an increase of miscarriage rate by about 4 percentage points. This study was collected on women who had had late term abortions in which a material called laminaria is used to dilate the cervix. Such abortions are rare in North America; 90% of abortions are done during the first trimester and do not involve laminaria. These data is not particularly useful. 7

bullet Richardson & Dickson: This is a British study published in 1976 which showed that the miscarriage rate after an abortion was 17.5% when compared to 7.5% for women who have not had an abortion. Unfortunately, these numbers appear quite inaccurate. They do not agree with the average miscarriage rate, reported by other researchers, of about 31%. Also, the study was made only a few years after abortion was legalized in Britain. The increase in miscarriage rates may well have been due to back alley abortions. The results do not appear to have been replicated by other studies. 8

bullet Koller & Eiklam: They reported that women who had had an abortion on their first pregnancy had the "the highest frequency of late spontaneous abortion and premature delivery." Unfortunately, the study is over 20 years old. Results do not seem to have been replicated elsewhere.

Planned Parenthood answers the question "Does an early abortion make miscarriage more likely in future pregnancies?" with a simple "No." 10

horizontal rule


There do not appear to be any convincing studies that would indicate that surgical abortions have any significant link to increased miscarriage rate -- at least for the first abortion.

One study may point to an increased rate after multiple abortions.

There seems to be no evidence at all that emergency contraception or non-surgical abortions increase the chances of later miscarriages.

horizontal rule


  1. Anthony R. Scialli, "Miscarriage: Executive Summary," at: The summary is based upon a report "Miscarriage" by the same author. Article copies can be obtained from: Chlorine Chemistry Council, 1300 Wilson Boulevard, Arlington, VA 22209. (703) 741-5829
  2. Andy Evangelista, "Study of Caffeine and Miscarriage Yields Surprise Finding About Decaf," 1997-AUG-25, at:
  3. "Abortion: Questions & Answers," Ohio Right to Life, at:
  4. "Maternal Complications," Catholic Information Center on Internet ™, at:
  5. Levin et al., "Association of Induced Abortion with Subsequent Pregnancy Loss," JAMA, vol. 243, no. 24, June 27, 1980, pp. 2495-2499
  6. Hilgers et al., "Fertility Problems Following an Aborted First Pregnancy." In New Perspectives on Human Abortion, edited by S. Lembrych. University Publications of America, 1981, pp. 128-134
  7. A. Kodasek, "Artificial Termination of Pregnancy in Czechoslovakia," Internat'l Jour. of GYN & OB, vol. 9, no. 3, 1971
  8. Richardson & Dickson, "Effects of Legal Termination on Subsequent Pregnancy," British Med. Jour., vol. 1, 1976, pp. 1303-4
  9. Koller & Eikham, "Late Sequelae of Induced Abortion in Primagravida" Acta OB-GYN Scand, 56 (1977) p. 311.
  10. "Abortion: Commonly asked questions," Planned Parenthood, at:

horizontal rule

Site navigation:

 Home page > "Hot" topics > Abortion > Medical problems > here

horizontal rule

Copyright 1998 to 2010,  by Ontario Consultants on Religious Tolerance
Latest update: 2010-JUN-23
Author: B.A. Robinson

line.gif (538 bytes)

horizontal rule

Go to the previous page, or return to the "Abortion - medical problems" menu, or choose:


Go to home page  We would really appreciate your help

E-mail us about errors, etc.  Hot, controversial topics

FreeFind search, lists of new essays...  Having problems printing our essays?

Twitter link

Facebook icon

GooglePage Translator:

This page translator works on Firefox,
Opera, Chrome, and Safari browsers only

After translating, click on the "show
original" button at the top of this
page to restore page to English.

Popular Pages

More Info

Twitter icon

Facebook icon

About this site
About us
Our beliefs
Your first visit?
Contact us
External links
Good books
Visitors' essays
Our forum
New essays
Other features
Buy a CD
Vital notes

World religions
 Christian def'n
 Shared beliefs
 Handling change
 Bible topics
 Bible inerrancy
 Bible harmony
Interpret Bible
 Beliefs & creeds
 Da Vinci code
 Revelation 666
Other religions
Cults and NRMs
Comparing Religions


About all religions
Main topics
Basic information
Gods & Goddesses
Handling change
Doubt & security
Confusing terms
End of the World?
True religion?
Seasonal events
Science vs Religion
More information

Morality & ethics
Absolute truth

Attaining peace
Religious tolerance
Religious freedom
Religious hatred
Religious conflict
Religious violence

"Hot" topics
Very hot topics
10 commandments
Abortion access
Assisted suicide
Death penalty

Same-sex marriage

Human rights
Gays in the military
Sex & gender
Spanking kids
Stem cells
Other topics

Laws and news
Religious laws
Religious news