Diethylstilbestrol (DES) is a strong synthetic estrogen, and animal studies suggest that estrogen affects the developing brain, including the part that governs sexual behavior and right and left dominance. The animal research indicated that human studies were needed, but most human studies about the effects of DES on psychosexual behavior were limited in size. This study of nearly 5,600 women and 2,600 men is the world’s largest cohort of individuals with documented prenatal exposure to DES (referred to as DES Daughters and Sons). Researchers concluded that not enough evidence was available to prove that DES affected the psychosexual behavior of adults.

Researchers mailed questionnaires to these DES Daughters and Sons to obtain information about marital status, sexual behavior, and handedness. Responses indicated that DES neither influenced sexual behavior nor resulted in an increased likelihood of homosexual contact. For DES Sons, DES was unrelated to the likelihood of ever having been married, age at first intercourse, number of sexual partners, and likelihood of having had a same-sex sexual partner in adulthood. DES Daughters were slightly more likely than unexposed women to have ever been married and were less likely to report having had a same-sex sexual partner; also, they were less likely than unexposed women to have had their first sexual intercourse before age 17 and were less likely to have had more than one sexual partner.

DES Daughters were just as likely as unexposed women to be left-handed. DES Sons were slightly more likely to be left-handed than unexposed men (14% vs. 11%, respectively). The researchers found no association between DES exposure and reported mental illness in DES Daughters, although the authors cautioned that this aspect may be under-represented due to the nature of self-reported data. In addition, no association was found between DES exposure and anorexia or bulimia.

Limitations that could influence study results include the style of self reporting and the likelihood of more participation by DES-exposed individuals than by unexposed individuals.

Citation: Titus-Ernstoff L, Perez K, Hatch EE, Troisi R, Palmer JR, et al. Psychosexual characteristics of men and women exposed prenatally to diethylstilbestrol. Epidemiology 2003;14:155-60.