During the 1970s and 1980s an increasing amount of public and scientific attention was paid to the health and medical problems of women and men whose mothers and grandmothers took diethylstilbestrol (DES) for prevention of miscarriage. A potent estrogenic chemical, DES was first developed in 1938 and initially became available in the U.S. for treating a range of gynecologic conditions in 1941 (Apfel and Fisher, 1984). A few years later its approval by the FDA was broadened to include treatment of pregnant women for the purpose of preventing miscarriages (spontaneous abortions). Though its efficacy had long been doubted by some in the medical community (Bambigboye and Morris, 2003; Dieckmann, 1953; Edelman, 1986), DES remained popular until publication of research in the early 1970s identifying an apparent association between prenatal exposure to DES and a rare form of vaginal cancer in females (commonly called “DES daughters”) whose mothers used DES (Giusti, Iwamato, and Hatch, 1995; Heinonen, 1973; Herbst and Bern, 1981).
It is estimated that as many as five to ten million Americans received DES during pregnancy or were exposed to the drug in utero between the late 1940s and early 1970s (Giusti, Iwamoto, and Hatch, 1995). The numbers of male offspring exposed in utero to DES (“DES sons”) have been estimated at between one and three million in the U.S. (Laitman, Jonler, and Messing, 1997) and similar estimates exist for the numbers of American females exposed in utero (Edelman, 1986). Hundreds of thousands of DES sons and daughters were also born in Canada, Europe and Australia during a similar period.
Compared with the history of research on the range of health effects of DES daughters, there are relatively few published medical research studies conducted with DES sons. And yet, the finding that prenatal DES exposure also led to detrimental effects for a number of exposed males has existed since the 1970s (Andonian and Kessler, 1979; Bibbo et al., 1977; Gill et al., 1979; Gill, et al., 1988; Laitman et al., 1997). These effects include a variety of structural abnormalities of the reproductive system such as epididymal (benign) cysts, hypoplastic testes or undescended testes (chryptorchidism), microphallus or underdeveloped penis which may be associated with an intersex condition, and hypospadias (opening of the penis is on the underside rather than at the end). Although DES exposure has been suspected as a possible source of male infertility and testicular cancer (Giusti, Iwamato, and Hatch, 1995, it is still uncertain whether prenatal DES exposure has led to increased risk of infertility (Wilcox et al., 1995) or increased rates of testicular cancer as well as other types of cancer in males (Strohsnitter, et al. 2001).