The drug diethylstilbestrol (DES) was previously prescribed to prevent spontaneous abortion and preterm delivery. DES was withdrawn in the 1970s when it became clear that it was associated with vaginal cancer and fertility disorders in women who were exposed to the drug prenatally. Flora Van Leeuwen and colleagues from The Netherlands Cancer Institute, Amsterdam, Netherlands, aimed to establish the risk of hypospadias (a birth defect in boys where the urethral opening occurs on the underside of the penis or the scrotum) in sons of women who were prenatally exposed to DES.
The investigators did a population study of around 8900 sons of over 16,000 women with fertility problems in The Netherlands. Mothers of 205 boys reported prenatal DES exposure. Four of these children were reported to have hypospadias. In the remaining 8729 children, only eight cases of hypospadias were reported, indicating that hypospadias was more than 20 times as common in boys whose mothers were exposed to DES.
In an accompanying Commentary (p 1081), Sonia Hernndez-Daz from Boston University School of Public Health, USA, concludes: "Although diethylstilbestrol is no longer used, research on exposure to this drug may be relevant to current concerns about exposures to weaker oestrogens such as synthetic hormones present in oral contraceptives, phyto-oestrogens in the diet, or certain pesticides or solvents. Knowledge gained from the diethylstilbestrol debacle should be used to guide research on the possible risks associated with oestrogens that are being encountered by current generations."