Women exposed to DES in utero have elevated risks of fertility impairment and adverse pregnancy outcomes.

According to a study women whose mothers took diethylstilbestrol (DES) during pregnancy are more likely than women who were not exposed to the drug in utero to experience delays in conceiving and are less likely ever to become pregnant. The study included 3373 women who were exposed to DES and 1036 unexposed controls who were enrolled in one of two longitudinal projects in the US. Three groups of women were compared: 1) women identified through review of medical records 2) women referred to the project by a physician or self-referral and 3) control group. These women completed a questionnaire that was mailed to them in 1994 asking about their health history pregnancies and pregnancy outcomes. Data showed that DES-exposed women were significantly more likely than others to have had difficulty conceiving. The analysis of adverse outcomes in any pregnancy yielded similar results for both groups of women who were exposed to DES. Based on these findings the researchers concluded that it is important for obstetrician-gynecologists to be aware of the consequences of DES exposure in utero on pregnancy outcome.