DES or diethylstilbestrol was given to women for more than three decades. The synthetic estrogen was prescribed to pregnant women as a means of preventing miscarriage, but the drug caused vaginal tumors, so the Food and Drug Administration pulled it from the market in 1971. Today, women do not receive DES during pregnancy, but the fetuses born to mothers given the drug are still facing the negative side effects. It appears the DES did more than cause tumors. According to a new research study published in the New England Journal of Medicine, DES may impact the immune system of the fetus causing problems for life.

When DES was pulled from the market in 1971, there was little reference to the potential long-term side effects of the anti-miscarriage drug, but today that impact is being noticed like a huge red flag. Women born to mothers give DES are being diagnosed with a rare form of uterine cancer, among other health problems linked to the drug. The synthetic estrogen did not just affect reproductive tissues, it also affected the immune system just like natural estrogen. Researchers believe the impact of DES on immune system development and “education” in-utero could be the cause of health problems women exposed to the drug are having today.

Many of the children born to DES-using mothers do not appear to have symptoms until they've passed through puberty. Researchers believe there is a sensitivity to sexual hormones that causes the sudden start of symptoms. This could also be the reason women born to mothers prescribed DES have increased risk of fertility problems, miscarriage and infertility.

This study clearly shows the impact of DES on the first generation of children born to DES using mothers, but it also poses a question. The drug was used primarily in the 40s, 50s and 60s. This generation of women would not be grandmothers, in some cases. Do the side effects of DES stretch beyond immediate contact or do they stop with the first generation offspring?

Source: Virginia Tech. New England Journal of Medicine. 11 October, 2011.