Exposure to DES is a lifelong health risk
28 February 2003
Tips to help identify and manage people exposed to diethylstilboestrol (DES) are contained in a new US report from the Centers for Disease Control.
DES, also known as stilbestrol, was widely prescribed to prevent miscarriage in Australia and overseas up until the early 1970s, but it was withdrawn from the market when some women exposed to the drug in utero — that is, exposed while they were developing in their mother’s uterus, because their mother was prescribed DES during pregnancy — developed vaginal clear cell adenocarcinoma (a type of cancer of the vagina) and reproductive tract abnormalities.
The US report outlines diagnostic tips for doctors to identify problems in women who took the drug while pregnant, and in their children exposed in utero. It also highlights recent research involving grandchildren of women who took the medication while pregnant (Journal of Midwifery and Women's Health 2003; 48: 19-29).
As a history of DES exposure is often not known or volunteered, researchers recommended that doctors always ask if a patient or her mother took DES, had problems carrying a pregnancy to term, had a history of miscarriages for which medication was prescribed, or had a history of ectopic pregnancy (a pregnancy outside the womb, usually in the fallopian tube).
The researchers stressed the importance of continuing to identify women exposed to DES in utero, who were now entering menopause. There is no known age beyond which exposed women are no longer at risk for vaginal adenocarcinoma, so lifelong screening is needed.
Women with extensive vaginal adenosis, structural abnormalities or the uterus or cervix, or clear cell adenoma of vagina or cervix should be assumed to have been exposed to DES, researchers said.
Women exposed to DES in utero should be counselled about the risk of infertility, ectopic pregnancy, miscarriage, premature labour and birth, and should be warned about the lack of research on the effect of oestrogens in the contraceptive pill on women who have been exposed to DES.
Women who took DES while pregnant had an increased risk of breast cancer, and needed a mammogram every 2 years after 40 years, the authors said.
Hormone replacement therapy should be used with caution in women who have been exposed to DES.
DES sons also face problems. Many have genital and sperm abnormalities, and those with undescended and hypoplastic (underdeveloped) testes risk developing testicular cancer. But no increase in male infertility has been noted.
There may also be health problems in DES grandchildren.
DES was listed on the Pharmaceutical Benefits Scheme under the alternative generic name stilbestrol until 1988, when it was withdrawn at the manufacturer's request.
Last Reviewed: 02 March 2003
- 1. Medical Observer Weekly 28/2/03
