Research has found little to no link between abortion and an increased risk of breast cancer.
Abortion is not considered one of the breast cancer risk factors, which include age, obesity, and family history of the disease.
While a small batch of studies has suggested a possible connection, an overwhelming amount of research indicates otherwise.
Concerns over a possible link between abortion and breast cancer have to do with changes in hormone levels during an abortion. Hormones like estrogen and progesterone can fuel the abnormal growth of breast cells.
There are two main types of abortion:
- Spontaneous abortion, or miscarriage, is the unintentional loss of a pregnancy in the first 20 weeks of gestation.
- Induced abortion is a medical or surgical procedure that ends a pregnancy.
Researchers have studied the effects of both types of abortion on breast cancer, and they haven’t found a connection.
Many of the studies that find no link between abortion and breast cancer are prospective cohort studies. In these studies, researchers start with a group of women who don’t have breast cancer. Then they follow those women over time to see if they develop breast cancer.
One of the biggest studies on the subject was published in the New England Journal of Medicine in 1997. It involved 1.5 million Danish women. Researchers adjusted for known breast cancer risk factors. They found no link between induced abortions and breast cancer.
Other studies have come to similar conclusions:
2004 analysisreviewed data from 53 studies that included 83,000 women with breast cancer across 16 countries. Researchers found neither spontaneous nor induced abortions increased breast cancer risk.
2008 studywith more than 100,000 U.S. women also found no link between induced or spontaneous abortions and breast cancer.
2015 reviewdidn’t find enough evidence to confirm any link, either.
A few retrospective case-control studies have found a connection between abortion and breast cancer. These studies compare women who have breast cancer with women who don’t by asking about their past health history.
It can be hard to get accurate results in these types of studies because some people may not remember exactly what they did in the past. Also, because abortion can be a stigmatized topic, some people may be hesitant to talk about it.
Some studies have found a link between abortion and breast cancer:
2014 meta-analysisincluded 36 studies. Researchers found that induced abortion was associated with breast cancer risk.
- A 2012 study with 1,300 Chinese women also found a link between abortion and breast cancer.
2018 meta-analysisof 43 studies confirmed that more research needs to be done.
Although the studies don’t all agree, many medical groups say most of the evidence does not show a link between abortion and breast cancer.
These groups include the
Abortion is a medical procedure. It can have risks like any other medical procedure. Some bleeding and cramping is expected afterward.
Signs of more serious side effects include:
- excessive bleeding
- severe pain
- high fever
- smelly vaginal discharge
Complications from an abortion can include:
- infection in the uterus
- excess bleeding
- damage to the cervix or uterus
- an incomplete abortion that requires another procedure
- premature birth in future pregnancies
People exposed to higher levels of estrogen — for example, because they’ve had their menstrual periods for a longer length of time or take birth control — have a slightly higher
Other risks include:
- Age and sex assigned at birth: Most breast cancers are diagnosed in people over age 50 who were assigned female at birth.
- Genes: Mutations to BRCA1, BRCA2, and other genes that run in families increase the risk.
- Early periods or late menopause: The earlier a person’s period starts and the later it stops, the longer their body is exposed to estrogen, which can increase the risk.
- Late or no pregnancy: Getting pregnant for the first time after age 30 or not having children can increase your risk.
- Taking birth control pills or hormone therapy: These pills contain estrogen, which can encourage breast cancer growth.
- Obesity: Obesity can increase the risk of breast cancer.
- Alcohol misuse: The more alcohol you drink, the more your risk increases.
Most medical groups agree that abortion does not appear to increase the risk of breast cancer.
If you have any concerns about your breast cancer risk, talk with a doctor to discuss early screening.