Study: DES Daughters at Increased Risk of Cancer, Fertility Problems

San Diego, CANow that studies have shown a link between diethylstilbestrol and cancer and have suggested other diethylstilbestrol side effects, all that the women who were born following a so-called DES pregnancy can do is wait and see whether or not they will be affected by their exposure to the drug. Unfortunately, they are at an increased risk of a variety of medical problems from a drug they were exposed to decades ago.

That is the reality that many women who were exposed to DES before birth now face. They have health problems related to a drug that they had no say in taking, a drug that was given to their mothers while pregnant to prevent miscarriages. A drug that was later found to be ineffective and has been linked to an increased risk of various types of cancer and fertility problems in women who were exposed to it while in the womb.

DES was the first synthetic form of estrogen and was used for decades to prevent pregnancy complications. Despite evidence in the 1950s that DES was not effective at preventing pregnancy complications, it was not until 1971 that the US Food and Drug Administration (FDA) issued a warning that DES should not be prescribed for pregnant women. By that time, as many as 10 million pregnant women and babies were exposed to DES.

A study, published in the New England Journal of Medicine (10/6/11), linked DES to 12 medical conditions, including a substantially increased risk of certain types of cancers. The risk of clear-cell adenocarcinoma is 40 times greater in women exposed to DES than in women not exposed, while the risk of breast cancer is 1.8 times greater. The risk of cervical intraepithelial neoplasia (precancerous cells in the cervix or vagina) is 2.3 times higher in women exposed to DES.

Despite the drug being used to prevent pregnancy complications, DES daughters (the women exposed to DES before birth) have an increased risk of their own pregnancy complications. This includes neonatal death, in which the risk is 8.0 times higher; pre-term delivery, 4.7 times higher; loss of second-trimester pregnancy, 3.8 times higher; and infertility, 2.4 times higher.

"Our study linked 12 adverse health outcomes in women to their exposure to DES in utero, with most risks increased by a factor of more than two as compared with the risks among unexposed women, resulting in substantial percentages of the exposed women having outcomes attributable to their exposure," researchers concluded.

DES side effects extend to men exposed to the drug, as well. Side effects in men include testicular abnormalities. It is not yet known what the risk of cancer is in DES sons.