DES Exposure: Questions and Answers

About 5 to 10 million people are thought to have been exposed to DES (diethylstilbestrol) during pregnancy from 1940 to 1971. Get up-to-date information on cancer risk and other potential health problems from DES exposure.

What is DES?

DES (diethylstilbestrol) is a man-made (synthetic) form of the hormone estrogen.

Doctors prescribed DES from 1940 until 1971 to help some pregnant women avoid problems with pregnancy. Though it was found to be ineffective, it was given to millions of women in the United States during this time.

In 1971, research came out that exposure to DES in the womb was linked with a rare type of cancer of the cervix and vagina. Soon after, the US Food and Drug Administration (FDA) advised doctors to stop prescribing it during pregnancy. A campaign was also started to tell the public about the problems DES could cause, but many people who were exposed to DES still don’t know it.

Since that time, research has shown that people exposed to DES may be at risk for several health problems.

Who was exposed to DES?

About 5 to 10 million people are thought to have been exposed to DES during pregnancy. This includes:

• DES mothers: Women who took DES while pregnant.
• DES daughters: Women whose mothers took DES while pregnant with them. This exposed them to DES while they were growing in the womb.
• DES sons: Men whose mothers took DES while pregnant with them. This exposed them to DES while they were growing in the womb.

Only those children who were in the womb at the time their mothers took DES were exposed to it. Brothers or sisters from pregnancies during which DES was not taken were not exposed.

How do you know if you were exposed to DES?

Any woman who was pregnant between 1940 and 1971 and had problems during her pregnancy or a previous pregnancy may have been given DES or another estrogen-like drug. But many women don’t know if they got DES while they were pregnant.

There are no medical tests to determine if you’ve been exposed to DES. If you think you or your mother took a hormone like DES during pregnancy, you can try to contact the hospital where you were born to ask if there is any record that your mother was given DES. Mothers and children have a right to see any of their remaining medical records.

Unfortunately, finding medical records after such a long time may not be possible. Most hospitals and doctors’ offices do not keep medical charts or records beyond a few years.

The county medical society or health department may be able to tell you where the records are, if they still exist. If you know where the prescription was filled, you might want to ask there, but many chain drugstores only keep records up to 10 years.

If you are able to get records, it may help to know that DES was sold under many different names. You can find a list of DES brand names at https://desaction.org/brand-names/.

DES mothers: Potential health problems

Women who were given DES during pregnancy might be at higher risk for certain health issues.

Breast cancer

Women who took DES appear to have an increased risk of breast cancer. Most research suggests that DES mothers have about a 30% higher risk of breast cancer than other women.

When looking at breast cancer risk during a woman’s lifetime, this means about 1 out of 6 women who took DES during pregnancy will get breast cancer, as opposed to about 1 out of 8 women who were not exposed to DES. Of course, many other factors affect breast cancer risk as well.

There are no other known health effects among DES mothers.

What should DES mothers do?

• Tell your doctor. Let your doctor know if you think you might have taken DES during pregnancy.
• Tell your children. Let your children know if they might have been exposed in the womb. They need to tell their doctors, so that this information can be included in their medical records.
• Get screened for breast cancer. Follow a regular schedule for early breast cancer detection, as is recommended for all women. Be aware of how your breasts normally look and feel. Report any breast changes to your health care team right away.

DES daughters: Risk for cancer and precancers

Women whose mothers took DES while pregnant with them may be at higher risk for some types of cancer.

Clear cell adenocarcinoma

DES is linked to a rare cancer called clear cell adenocarcinoma (CCA) in a very small number of daughters of women who used DES during pregnancy. While risk of this cancer is increased among DES daughters, it is still very rare.

Breast cancer

Many studies have looked at breast cancer risk in DES daughters. Some have found a slightly increased risk of breast cancer among DES daughters, but others have found that that the risk isn’t any higher.

Pancreatic cancer

Some research suggests that DES daughters might be more likely to develop pancreatic cancer than women in general.

Cervical precancers

About 4% of DES daughters develop abnormal cells in the cervix and vagina, also called cervical precancers. These are not cancers, but they might develop into cancer if not treated. This risk is about twice as high as in women not exposed to DES.

DES daughters: Other health issues

The following are other potential health problems for women whose mothers took DES while pregnant with them.

Reproductive issues

DES daughters are more likely to experience problems getting pregnant or during pregnancy, including premature births, ectopic pregnancies, and miscarriages. However, at this time, DES daughters are largely past their reproductive years.

Depression

One study found that DES daughters were more likely to be diagnosed with depression. However, later studies found no increased risk of depression among DES daughters.

Heart disease

DES daughters are at a higher risk of heart problems, including high cholesterol, high blood pressure, and heart disease.

What should DES daughters do?

• Tell your doctor. Some problems, such as clear cell adenocarcinoma, are usually found only when a doctor is looking for them. This is why it’s important to let your doctor know if you think you were exposed to DES.
• Get recommended screening exams and tests. Get screened for breast cancer at the recommended screening intervals. Also, get screened for cervical cancer as recommended.

In the past, additional tests such as yearly pelvic exams were recommended to screen for clear cell carcinoma and other problems, but it’s not clear until what age these screenings should continue. Ask your health care team if they recommend any additional exams or tests.

DES sons: Health risks

The following are potential health problems for men whose mothers took DES while pregnant with them.

Genital abnormalities

DES sons are more likely to have genital abnormalities, like undescended testicles or cysts in the epididymis. They also may be at a higher risk for testicle inflammation and infection.

DES sons don’t seem to have more fertility problems than other men. Studies have been done to see if they are at a higher risk of testicular cancer, but the results are unclear.

Heart problems

DES sons are at a higher risk of heart problems, including high cholesterol, high blood pressure, and heart disease.

What should DES sons do?

There are no special screenings or tests recommended for DES sons, but they

should tell their doctors about their exposure and get regular exams. DES sons may want to talk to their doctors about whether they should examine their testicles regularly.

DES grandchildren

DES grandchildren are the children of DES sons or DES daughters. They are also being studied because researchers have found that some gene changes caused by DES in DES sons and daughters might be passed on to their children.

Some research has suggested that DES granddaughters might begin their menstrual periods at later ages and be more likely to have irregular menstrual cycles. They might also have a higher risk of infertility and preterm birth than other women. But these findings are based on small numbers of events, and more research is needed.

Research is ongoing to determine whether DES grandchildren are at a higher risk for any other health problems.

DES research

Researchers around the world continue to study people who have been exposed to DES, their children, and their grandchildren to look for possible health effects. Some people known to have been exposed to DES are being watched in the National Cancer Institute’s DES Follow-up Study, which was started in 1992.