Diethylstilbestrol (DES)

After reading this handout you will know what diethylstilbestrol (DES) is and what conditions it has been used to treat. You will also find out what physical problems have been found in mothers and children of mothers who took DES during their pregnancies.

What is diethylstilbestrol (DES)?

Diethylstilbestrol (DES) is a synthetic (man-made) estrogen that has been used:

• to treat underdeveloped ovaries
• to treat the symptoms of menopause such as hot flashes, sweating, and dryness of the vagina
• to treat problems with menstruation
• to stop milk production in mothers who do not want to nurse
• as an after-sex contraceptive.

In the past, it was believed that DES could prevent miscarriages, preterm labor, and other complications of pregnancy. From 1941 to 1971, 4 to 6 million American women were given DES during pregnancy. However, mothers and the children of mothers who took DES are at risk for certain reproductive problems. As a result, in 1971 the federal drug administration issued a warning that DES should not be given to pregnant women.

How are mothers who took DES affected?

Mothers who took DES have an increased risk of breast cancer. Also, some researchers believe that any added estrogen could increase this risk of breast cancer. Therefore, if you are one of the mothers who took DES, you may not want to have estrogen replacement therapy. Ask your health care provider about this.

How are sons of mothers who took DES affected?

Researchers and doctors discovered that the children of mothers who took DES during pregnancy were more likely to have certain problems when they reached puberty. Sons were born with abnormal urinary and reproductive tracts. Some have developed cancer of the testicles. Others have poor sperm production and are infertile. Because of the increased risk of cancer of the testicles, DES sons should check themselves on a monthly basis by gently rolling their testicles between their fingers. If a lump is discovered, it should be reported at once to a health care provider. DES sons who fail to create a pregnancy after a year of trying might consider seeing an infertility specialist.

If I am a DES daughter, how might I be affected?

• The most common change is the presence of a type of tissue in the vagina called adenosis. This tissue is normally found in the cervical canal (opening to the uterus), but in DES daughters it is also found in the vagina. Because adenosis produces mucus, you may have a discharge that can be mistaken for an infection. This discharge does not need treatment and will lessen as the adenosis lessens. Adenosis is usually covered by normal tissue over time. It is usually no longer visible once you are over 30 years old.
• You may have an extra ridge of tissue growth on the cervix that looks like a collar or hood. This may make it difficult to use a diaphragm for birth control. The ridge may disappear over time.
• Other structural changes you may have are a small or T-shaped uterus and abnormal fallopian tubes. This can make getting pregnant and carrying a baby to full term difficult. There is also a greater chance that the baby will start to grow in one of the fallopian tubes (ectopic pregnancy).
• A small number (1 in 1,000) of DES daughters develop a rare cancer of the vagina or cervix called clear cell adenocarcinoma. This usually appears between 15 and 27 years of age. If found early, this cancer can be treated with surgery and radiation. Some women who were treated have later had recurrences of cancer in their lungs and other parts of their body.

When should I see my health care provider about this concern?

If your mother was given DES while she was pregnant with you, you should see a women's health care specialist as soon as you begin menstruating or by age 14. You should have a pelvic exam and Pap smear at least once a year thereafter or more often if your provider recommends it.

What is included in a DES exam?

• Your health care provider will carefully look at and feel your vagina and cervix for any physical differences.
• Your provider will swab your cervix and vagina with a long swab (Pap smear) and send the sample to the lab to be looked at under a microscope.
• Your provider will paint your vagina and cervix with iodine to check for abnormal tissue. Normal tissue stains brown and adenosis does not stain.

Depending on the results of these tests, other procedures may be necessary, such as colposcopy (looking at your vagina and cervix through a magnifying glass) and biopsy (taking a small amount of tissue to be checked in the laboratory).

If I am a DES daughter, can I have normal pregnancies?

Many DES daughters have no problem getting pregnant and have normal pregnancies. However, because of the possible structural abnormalities of the reproductive organs and adenosis, you may have menstrual irregularities and problems getting pregnant and carrying a baby to full term.

If you become pregnant, it is important to get medical care from a health care provider familiar with the problems DES daughters may have. Your higher risk for ectopic pregnancies makes it important for you to see your provider as soon as you think you are pregnant. Your provider will want to make sure the pregnancy is in your uterus. In ectopic pregnancies the pregnancy is in the fallopian tubes, cervix, ovary, or abdomen. An ectopic pregnancy can threaten your life and must be ended as soon as possible.

Your risk for miscarriage and premature birth also are higher, so you need to learn the signs and symptoms of these problems from your prenatal care provider as soon as possible. You will need to see your provider frequently (weekly to biweekly) during your pregnancy. If your risk for miscarriage is great, it may be recommended that your cervix be stitched closed (cerclage) until labor begins.

Can I use birth control pills?

Recent studies indicate that women exposed to DES can take birth control pills without added risk.