February 23, 2000

WESTPORT, Conn. (HealthScout)-Women who have problems conceiving or who suffer repeated miscarriages might want to do a little research into their own mother's medical history. A hormone known as DES, or diethylstilbestrol, may actually be to blame, and more than a half century after it was first used, scientists finally know why.

Any woman aged 29 or older is potentially at risk if their mothers were prescribed DES. The synthetic estrogen was discontinued in 1971. Men whose mothers took DES may also have reproductive tract abnormalities but no decrease in fertility. A consumer group called DES Action USA has more information on the hormone's effect on fertility and reproductive cancer in women.

Doctors originally prescribed the drug because they mistakenly believed that low estrogen levels during pregnancy led to miscarriage. But it was also given to women who were not at risk for miscarriage and even as a treatment for acne and cancer. Science News explains that when DES is given during pregnancy it suppresses a gene essential for the development of the immune system.

DES has the most potent effect on reproduction of any estrogen known. A technical abstract from the journal Environmental Health Perspectives reviews what DES does on the cellular and molecular level. Specialists in reproductive toxins warn that other estrogen-like compounds could have similar -- albeit, more subtle -- effects. Environmental estrogens include pesticides, certain chemicals in plastic and a wide variety of plants