What is DES?

DES (diethylstilbestrol) is a man-made (synthetic) form of estrogen, a female hormone. Doctors prescribed it from 1938 until 1971 to help some pregnant women who had had miscarriages or premature deliveries in the past. At that time it was believed that these problems might have been caused by low levels of estrogen in the woman's body. DES was used to correct this problem. It was given to about 4 million women in the United States during this time.

DES was used less in the 1960s, after studies showed that it might not help women carry pregnancies to full term. Later, it was learned that infants whose mothers took DES during the first 5 months of pregnancy were more likely to have problems in their reproductive systems. In 1971, the Food and Drug Administration advised doctors to stop prescribing it during pregnancy. A campaign was also started to tell the public about the problems DES could cause. And doctors were urged to tell patients who may have taken the drug. But there was no good way to tell every person who was exposed to DES. Many people who were exposed to DES as a fetus still don't know it. They also may not know that the effects of DES are still being studied.

Estrogens are still prescribed for some medical reasons, including some cancers, but they are no longer used during pregnancy. Other than in a rare clinical trial, DES is no longer available in the United States for use in humans.

Who was exposed to DES?

About 5 to 10 million people were thought to be exposed to DES during pregnancy. Three groups of people were exposed:

• DES mothers: women who took DES while pregnant

• DES daughters: women whose mothers took DES when pregnant with them. This exposed them to DES while they were growing in the womb

• DES sons: men whose mothers took DES when 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 in which DES was not taken were not exposed.

How do you know if you (or your mother) took DES during pregnancy?

Many people don't know if they were exposed to DES.

Many women do not recall if they got DES while they were pregnant. Any woman who was pregnant between 1938 and 1971 and had problems during the current or a previous pregnancy may have been given DES or another estrogen-like drug. Women who did not have problems are less likely to have been given DES. Women who were not under a doctor's care while pregnant most likely did not take DES either, because you could only get it with a doctor's prescription. DES was given in pills, injections, and vaginal suppositories (sometimes called pessaries).

Checking medical records

If you think you (or your mother) took a hormone like DES during pregnancy, you should try to contact the doctor who managed the pregnancy or the hospital where you were born to ask if there is any record that you (or your mother) were given DES. Keep in mind that many hospitals and doctors' offices do not keep medical charts or records beyond a few years.

If you took any pills or got shots or suppositories during pregnancy, find out if medical records of your pregnancy still exist. You may be able find out the name of the drugs you were given. Mothers and children have a right to see any of their remaining medical records.

Finding medical records after a long period of time may be hard to do. If the doctor has moved, retired, or died, another doctor may have taken over the practice as well as the records. The county medical society or health department may be able to tell you where the records are. A few pharmacies keep prescription records for a long time, but many chain drugstores keep them 10 years or fewer. If you know where the prescription was filled, you may want to ask there. Military medical records are kept for 25 years.

If you are able to get records, it is helpful to know that DES was sold under many different names. The Centers for Disease Control and Prevention (CDC) has a list of DES brand names on their Web site (www.cdc.gov/des/hcp/brand/index.html). Two of the most commonly used names were stilbestrol and DESPlex, but there are dozens more.

If you can't find out for sure

In many cases, it may be impossible to find out if DES was used. And there are no medical tests that can tell you if you were exposed to DES. This is why it is important to keep any records you may already have about DES exposure. Write down and save anything you are able to find out about dates the drug was taken, and other details.

If you cannot find this information and are unsure of your exposure, you can get more information about DES and an online version of the CDC's DES Update Self-Assessment Guide to help you figure out how likely it was that you were exposed to DES. It can be found on the Web at www.cdc.gov/des/consumers/guide/index.html. Or you can get a print version by calling the CDC's toll-free number found in the "Additional resources" section at the end of this document.

What health problems might women who took DES during pregnancy have?

Breast cancer

Women who took DES appear to have an increased risk of breast cancer. Most research suggests that the risk of breast cancer in DES-exposed mothers is about 30% higher than the risk of women who have not been exposed to this drug. 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 of DES exposure in pregnant women who took this drug.

What should women who took DES while they were pregnant do?

A woman who took DES while pregnant (or suspects she may have been given it) should tell her doctor. If possible, she should try to find out the dose, when the medicine was started, and how it was used.

She also should tell her children who were exposed in the womb. They need to tell their doctors, so that this information can be included in their medical records.

The National Cancer Institute (NCI) recommends that DES-exposed mothers follow a regular schedule for early breast cancer detection, as is recommended for all women. This should include mammograms and clinical breast exams. If they have other risk factors for breast cancer, they may need MRI (magnetic resonance imaging) along with their yearly mammograms. Women who took DES while they were pregnant should report any new breast lumps or other breast changes to a doctor right away. These women should also have regular medical check-ups.

What health problems might DES-exposed daughters have?

Clear cell adenocarcinoma

In 1971, DES was first linked to a rare cancer called clear cell adenocarcinoma (CCA) in a very small number of daughters of women who used DES during pregnancy. This cancer of the vagina and cervix usually occurs in DES-exposed daughters in their late teens or early 20s. But it has been reported as early as age 8, and the upper age limit, if any, is not known. Some cases have been reported in women in their 30s and 40s. Now that DES-exposed daughters are older than 30, the number of reported DES-related cases of clear cell adenocarcinoma has gone down, but the risk may still be higher than in women who were not exposed.

DES-exposed daughters are about 40 times more likely to develop this cancer than women not exposed to DES in the womb. But because this cancer is rare to begin with, this means that about 1 of every 1,000 DES-exposed daughters might develop CCA.

Treatment for CCA will vary depending on the location and stage (extent) of the cancer. For more information on the treatment of clear cell adenocarcinoma, please see our documents, Vaginal Cancer or Endometrial Cancer.

Abnormal cells in the cervix and vagina

Some scientists have found a link between DES exposure before birth and a higher risk of abnormal cells starting to grow in the cervix and vagina. Doctors use a number of terms to describe these abnormal cells including dysplasia, cervical intraepithelial neoplasia (CIN), and squamous intraepithelial lesions (SILs). These abnormal cells look like cancer cells. But they do not spread into nearby healthy tissues like cancer cells do.

These cellular changes usually take place when women are between 25 and 35 years old, but may happen at other ages, too. This condition is not cancer, but it may develop into cancer if it's not treated. The National Cancer Institute recommends that DES-exposed daughters have a yearly Pap test and pelvic exam to check for dysplasia, or abnormal cells. American Cancer Society guidelines also recommend special Pap tests every year for these women, even after age 30 (after age 30, women who have not been exposed to DES may only need Pap tests every 2 or 3 years).

Structural changes in the female reproductive tract

DES-exposed daughters may have a vagina, uterus, or cervix with an unusual shape or form (structure). Most of these changes do not cause medical problems. But some may cause problems for women who want to get pregnant or cause other reproductive health problems.

Problems getting pregnant

Early studies of fertility rates among DES-exposed daughters did not produce clear results, but a more recent study found that DES-exposed daughters are more likely to have fertility problems. The study found that 28% of women who had been exposed to DES didn't get pregnant after trying for at least 12 months, compared with 16% in women who were not exposed to DES. The most recent study of infertility among DES-exposed daughters found that 24% had never gotten pregnant, compared with 18% of women who were not exposed to DES.

At least part of this difference seems to be caused by changes in the shape of the uterus. DES-exposed daughters may also be more likely to have irregular menstrual periods, which could add to fertility problems.

It's important to note that although DES-exposed daughters are at higher risk for fertility problems, most do not have problems becoming pregnant.

Problems during pregnancy

DES-exposed daughters may also have a higher risk of certain problems during pregnancy. According to a study done in 2000, these problems include:

Premature birth

Among DES-exposed daughters, about 64% delivered a full-term baby in their first pregnancy, compared with 85% in women who were not exposed to DES.

Tubal (ectopic) pregnancy

The risk of an ectopic pregnancy (where the egg implants in an area other than the uterus and poses a danger to the mother) was found to be 3 to 5 times higher in DES-exposed daughters.

Miscarriage

Almost 20% of DES-exposed daughters miscarried their first pregnancy, compared with about 10% among women not exposed to DES.

Reducing the risks during pregnancy

Because these problems may show up during pregnancy, DES-exposed daughters need to tell their doctors about their DES exposure. It's best if they do this before they become pregnant. This way they can work with their doctors to watch for signs of problems and deal with them as soon as possible. For instance, some may want to talk with their doctors about the early symptoms of ectopic pregnancy, so that if it happens, it can be treated quickly. Their pregnancies will probably be treated as high-risk, meaning these women will be closely watched by their doctors throughout the pregnancy.

Again, it's important to note that most DES-exposed daughters have no problems getting pregnant or carrying a baby to full term. All women should have good prenatal care, but it's even more important for DES-exposed daughters.

Other possible problems

A recent study seems to suggest that DES-exposed daughters also may have a slightly increased risk for breast cancer. The risk seems higher after age 40. The risk of other cancers does not seem to be increased, but research continues in this area.

Children of DES-exposed sons and daughters

At this time, there is no evidence that the risk of birth defects, other abnormalities, or cancer is any greater for children born to DES-exposed daughters and sons than for other children. See the section "DES research" for more information.

What should DES-exposed daughters do?

If you were born between 1938 and 1971, and you think that your mother may have been given DES, try to learn how long and at what point in her pregnancy she took the drug. Or you can try to find records from her obstetrician's office. (See the section, "How do you know if you [or your mother] took DES during pregnancy?") Women who believe they may have been exposed to DES before birth should be aware of the possible health effects of DES and tell their doctors about their exposure. Some problems, such as clear cell adenocarcinoma, are usually found only when the doctor is looking for them. This is why it's important that your doctor know about the possible problems linked to DES exposure.

DES-exposed daughters should keep records about their exposure, and get regular gynecologic exams throughout their lifetimes. The American Cancer Society recommends that DES-exposed daughters get yearly Pap tests as long as they are in good health, even if they have had a hysterectomy. The National Cancer Institute (NCI) recommends these women have regular, thorough exams that may include the following:

Pelvic exam

This is a physical exam of the reproductive organs. An exam of the rectal area also should be done.

Palpation

As part of a pelvic exam, the doctor feels the vagina, uterus, cervix, and ovaries for any lumps. Sometimes, feeling for lumps is the only way to find an abnormal growth.

Pap test

A routine Pap test is not enough for DES-exposed daughters. The cervical Pap test must be done along with a special Pap test of the vagina called a four-quadrant Pap test, in which cell samples are taken from all sides of the vagina.

Iodine staining of the cervix and vagina

An iodine solution is used to briefly stain the linings of the cervix and vagina. This helps the doctor find adenosis (a non-cancerous but abnormal growth of glandular tissue) or other abnormal tissue.

Colposcopy

A magnifier is used to look at the vagina and cervix. Some doctors do not do this for everyone, but if the Pap test result is not normal, it is very important to look closely for abnormal tissue.

Biopsy

Small samples of any tissue that looks abnormal on other tests are removed and looked at under a microscope to see whether cancer cells are present.

Breast exams

While it is not known for sure if DES-exposed daughters have a higher risk for breast cancer, they should follow current screening recommendations.

Is it safe for DES-exposed daughters to use oral contraceptives (birth control pills) or hormone replacement therapy?

Each woman should talk about this with her doctor. Studies have not shown that birth control pills or hormone replacement therapy is unsafe for DES-exposed daughters, but some doctors believe DES-exposed daughters should avoid them because of the estrogen in them. Structural changes in the vagina or cervix do not usually cause problems with the use of other forms of contraception, such as diaphragms, female condoms, or spermicides.

What health problems might DES-exposed sons have?

Epididymal cysts

DES-exposed sons have an increased risk for epididymal cysts, which are non-cancerous growths on the testicles. Some studies have found that as many as 1 out of 5 DES-exposed sons may develop these.

Other problems

Whether DES-exposed sons are at higher risk for other genital changes is not known. Some studies have found that DES-exposed sons may have a higher risk of problems with their testicles, such as undescended testicles or abnormally small testicles. But other studies have not found these risks. The possible relationship of DES exposure to increased risk of testicular or prostate cancer is not clear at this time.

DES-exposed sons seem to have no more fertility problems than other men.

What should DES-exposed sons do?

There are no special screenings or tests for DES-exposed sons, but they should tell their doctors about their exposure and get regular exams from their doctors. Even though DES-exposed sons have not been found to have a higher risk of developing cancer, males with undescended testicles or unusually small testicles have a higher risk of testicular cancer, whether or not they were exposed to DES. DES-exposed sons may want to consider examining their testicles regularly.

DES research

People known to have been exposed to DES are being watched in the NCI's DES Combined Cohort Follow-up Study, which was started in 1992. At that time, another education campaign was begun for doctors and for the public. Researchers are following up with about 15,000 people to look for other possible effects of DES, such as higher risks of breast and testicular cancers, as well as other health issues that might not be as easily linked to DES exposure. This research is still going on, and study results continue to be published. The Follow-up Study also includes the children of the daughters and sons who were exposed to DES -- the third generation of DES-exposed families. At this time, there are no data to clearly support that DES is harming the third generation in any way. One small study in the Netherlands suggested that the sons of DES daughters had a fairly high risk of a birth defect called hypospadias. (In this defect, the urethra opens along the shaft of the penis rather than at its tip.) A later study suggested that the risk of hypospadias was much smaller than it was first thought to be. The third generation will continue to be studied, along with the mothers who were first exposed to DES and their children.

Additional resources

National organizations and Web sites*

Along with the American Cancer Society, other sources of information and support include:

Centers for Disease Control and Prevention (CDC)
DES Update Home
Toll-free number: 1-800-CDC-INFO (1-800-232-4636)
Web site: www.cdc.gov/des
Has up-to-date information about the health effects of DES, as well as screening and treatment options for DES-exposed groups. Web site also has a DES Self-Assessment Guide to help people figure out if they might have been exposed to DES between 1938 and 1971. Research on the children of DES daughters is also available on the site.

Centers for Disease Control and Prevention (CDC)
National Breast and Cervical Cancer Early Detection Program (NBCCEDP)
Toll-free number: 1-800-CDC-INFO (1-800-232-4636)
Web site: www.cdc.gov/cancer/nbccedp
Provides access to breast and cervical cancer screening services for underserved women in the U.S.

Centers for Medicaid and Medicare Services (CMS)
Toll-free number: 1-800-MEDICARE (1-800-633-4227)
Web site: www.cms.hhs.gov
For information on Medicare eligibility and coverage

DES Action USA
Toll-free number: 1-800-DES-9288 (1-800-337-9288)
Web site: www.desaction.org
For information, referrals, and support for DES-exposed people. Also has a list of doctors (by state) who have experience caring for DES-exposed daughters

National Cancer Institute
Toll-free number: 1-800-4-CANCER (1-800-422-6237)
Web site: www.cancer.gov
DES FactSheet is available at www.cancer.gov/cancertopics/factsheet/Risk/DES;
also offers information on screening and treatment for cancer

Registry for Research on Hormonal Transplacental Carcinogenesis
Telephone: 773-702-6671 (collect calls accepted)
Web site: http://obgyn.bsd.uchicago.edu/registry.html
A world-wide registry for people with clear cell adenocarcinoma of the vagina and/or cervix and those who do not know if they were exposed to DES or other synthetic hormones before birth

*Inclusion on this list does not imply endorsement by the American Cancer Society.

No matter who you are, we can help. Contact us anytime, day or night, for information and support. Call us at 1-800-227-2345 or visit www.cancer.org.

References

Centers for Disease Control and Prevention. CDC's DES Update; 2005. Accessed at www.cdc.gov/des/consumers/download/cdc_des_update.pdf on August 24, 2009.

Centers for Disease Control and Prevention. Known DES Health Effects. Accessed at www.cdc.gov/des/consumers/download/know4_effects.pdf on August 24, 2009.

Centers for Disease Control and Prevention. Potential Health Risks for Third Generation (Offspring of DES Daughters and Sons). Accessed at www.cdc.gov/des/consumers/about/concerns_offspring.html on August 21, 2009.

DES Cancer Network, The. Health Care Guidelines for DES-exposed Women and Men. Accessed at www.descancer.org/care.html on August 24, 2009.

National Cancer Institute. FactSheet: DES Questions and Answers. 2006. Accessed at www.cancer.gov/cancertopics/factsheet/Risk/DES on August 21, 2009.

Hatch EE, Herbst AL, Hoover RN, et al. Incidence of squamous neoplasia of the cervix and vagina in women exposed prenatally to diethylstilbestrol (United States). Cancer Causes Control. 2001;12:837-845.

Kaufman RH, Adam E. Findings in female offspring of women exposed in utero to diethylstilbestrol. Obstet Gynecol. 2002;99:197-200.

Kaufman RH, Adam E, Hatch EE, et al. Continued follow-up of pregnancy outcomes in diethylstilbestrol-exposed offspring. Obstet Gynecol. 2000;96:483-489.

Klip H, Verloop J, van Gool JD, et al. Hypospadias in sons of women exposed to diethylstilbestrol in utero: a cohort study. Lancet. 2002;359:1102-1107.

Palmer JR, Hatch EE, Rao RS, et al. Infertility among women exposed prenatally to diethylstilbestrol. Am J Epidemiol. 2001;154:316-321.

Palmer JR, Wise LA, Robboy SJ, et al. Hypospadias in sons of women exposed to diethylstilbestrol in utero. Epidemiol. 2005;16:583-586.

Palmer JR, Wise LA, Hatch EE, et al. Prenatal diethylstilbestrol exposure and risk of breast cancer. Cancer Epidemiol Biomarkers Prev. 2006;15:1509-1514.

Saslow D, Runowicz CD, Solomon D, et al. American Cancer Society guideline for the early detection of cervical neoplasia and cancer. CA Cancer J Clin. 2002;52:342-362.

Schechter T, Finkelstein Y, Koren G. Pregnant "DES daughters" and their offspring. Can Fam Physician. 2005;51:493-494.

Tedeschi CA, Rubin M, Drumholz BA, Six cases of women with diethylstilbestrol in utero demonstrating long-term manifestations and current evaluation guidelines. J Low Genit Tract Dis. 2005;9:11-18.

Titus-Ernstoff L, Troisi R, Hatch EE, et al. Offspring of women exposed in utero to diethylstilbestrol (DES): a preliminary report of benign and malignant pathology in the third generation. Epidemiology. 2008;19:251-257.

Troisi R, Hatch EE, Titus-Ernstoff L, et al. Cancer risk in women prenatally exposed to diethylstilbestrol. Int J Cancer. 2007;121:356-360.

Last Medical Review: 08/27/2009
Last Revised: 08/27/2009