DES - Diethylstilbestrol, Part 2

by National Cancer Institute

(Page 2 of 2)

7. What should DES-exposed mothers do?

A woman who took DES while pregnant (or suspects she may have taken it) should inform her doctor. She should try to learn the dosage, when the medication was started, and how it was used. She also should inform her children who were exposed before birth so that this information can be included in their medical records. DES-exposed mothers should have regular breast cancer screening and yearly medical checkups that include a pelvic examination and a Pap test.

8. What should DES-exposed sons do?

DES-exposed sons should inform their physician of their exposure and be examined periodically. While the level of risk of developing testicular cancer is unclear among DES-exposed sons, males with undescended testicles or unusually small testicles have an increased risk of developing testicular cancer, whether or not they were exposed to DES.

9. Is it safe for DES-exposed daughters to use oral contraceptives or hormone replacement therapy?

Each woman should discuss this important question with her doctor. Although studies have not shown that the use of birth control pills or hormone replacement therapy are unsafe for DES-exposed daughters, some doctors believe these women should avoid these medications because they contain estrogen. Structural changes in the vagina or cervix should cause no problems with the use of other forms of contraception, such as diaphragms or spermicides.

10. Do DES-exposed daughters have unusual problems with fertility and pregnancy?

A 1980 study of DES-exposed and unexposed daughters participating in the National Cooperative Diethylstilbestrol Adenosis Study (DESAD) found that fertility did not differ between the two groups. However, this study found an increased risk of premature births, miscarriage, and ectopic pregnancy associated with DES exposure.

A followup study published in 2001 examined DES-exposed and unexposed daughters from the DESAD project and DES-exposed and unexposed daughters from another study group known as the Chicago cohort. The Chicago cohort consisted of daughters whose mothers participated in an early clinical trial (research study) that tested the effectiveness of DES during pregnancy. The clinical trial was conducted at the University of Chicago. The followup study found that DES-exposed daughters have a higher risk of infertility than unexposed women, and the increased risk of infertility is mainly due to uterine or tubal problems. The researchers suggested that the difference in the findings between the two studies may be attributed to the age of the participants. The earlier study evaluated data from women who were primarily between ages 25 and 30. The followup study not only analyzed data from a larger number of participants but also covered a longer time period, so the women were closer to the end of their reproductive years.

In another analysis of data published in 2000, researchers evaluated the long-term pregnancy experiences of DES-exposed daughters compared with unexposed daughters. They found that DES daughters were more likely to have had premature births, miscarriage, or ectopic pregnancy. Full-term infants were delivered in the first pregnancies of 64. percent of exposed women compared with 84.5 percent of unexposed women.

Though there is evidence that the risk of ectopic pregnancy, miscarriage, and premature birth is increased for DES-exposed daughters, most DES-exposed daughters do not experience DES-related problems during pregnancy. If a DES-exposed daughter becomes pregnant, the doctor should be told of the DES exposure and should monitor the pregnancy closely.

11. What is the focus of current research on DES exposure?

Researchers continue to study DES-exposed daughters as they move into the menopausal years. The cancer risks for exposed daughters and sons are also being studied to determine if they differ from the unexposed population. In addition, researchers are studying possible health effects on the grandchildren of mothers who were exposed to DES during pregnancy (also called third-generation daughters or DES granddaughters).

Two published studies have examined DES granddaughters for possible abnormalities. A 1995 study found that the age menstruation began was not affected by the mother's exposure to DES. In a 2002 study, researchers compared DES granddaughters' pelvic exams to the results of their mothers' first pelvic exams. None of the granddaughters' pelvic exams showed changes usually associated with DES exposure. The researchers concluded that third-generation effects of in utero DES exposure are unlikely.

Researchers are also studying the theory that exposure to DES may lead to an increased risk of breast cancer. A 2002 analysis found that DES exposure in utero was associated with a slightly increased risk of breast cancer. The experience of the women thus far suggested that increased risk might be restricted to women age 40 or older, and to tumors that have estrogen receptors (need the hormone estrogen to grow), but both observations are uncertain at this point because of the relatively small number of women diagnosed to date. The researchers concluded that more followup of women exposed to DES in utero is needed to further clarify these findings.

A study published in 2003 found little support for the hypothesis that in utero exposure to DES influences the psychosexual characteristics (the likelihood of ever having been married, age at first intercourse, number of sexual partners, and having had a same-sex sexual partner in adulthood) of adult men and women.

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