DES (diethylstilbestrol) was utilized for decades to prevent threatened abortion but was ineffective and produced significant genitourinary tract abnormalities in women as well as functional irregularities. Some investigators have suspected a possible link between immune irregularities caused by DES exposure in utero with these abnormalities. It is known that an immune response is critical to prevent the spread of infections and tumors in humans.
DES was even used therapeutically in men with prostate cancer for many years in some of the men who responded to the treatment, there was evidence of enhanced immune system function. It has therefore been speculated that intrauterine DES exposure in women may have been associated with an exaggerated or heightened immune response and the following link discusses this point further.
Eight women with known exposure to DES in utero were studied by Ways et al. in 1987 (28). All had evidence of impaired fertility and abnormal tissue growth such as cervical adenosis and squamous metaplasia with one case of vaginal cancer. These 8 women were matched with 8 healthy control women of similar age who were fertile and unexposed to DES. The immune responses of these two groups of women were studied carefully in the laboratory.
Diethylstilbestrol exposed women showed a significantly enhanced immune response in certain cells called T-lymphocytes compared to the control group. The investigators suspected that diethylstilbestrol altered the DNA of these cells in some way leading to the enhanced immune response. They further suggested that such an enhanced immune response could lead to infertility by damaging sperm or reducing sperm penetration.
28. Ways S.C. et al. Alterations in Immune Responsiveness in Women Exposed to Diethylstilbestrol in Utero. Fertility and Sterility. 48; 2: 193-197, August 1987.