Prenatal diethylstilbestrol exposure and risk of obesity in adult women.

Diethylstilbestrol (DES) is a non-steroidal estrogen that was commonly prescribed during pregnancy from the late 1940s to 1971. A potent endocrine disruptor, prenatal DES exposure has been linked with reproductive tract malformations, adverse pregnancy outcomes, cancer, infertility and earlier menopause. DES was used for years as a growth promoter in animal production. Some animal studies suggest that prenatal DES exposure is associated with obesity and metabolic disturbances. Using data from the National Cancer Institute DES Follow-Up Study, we evaluated the association between DES and adult obesity, weight gain from age 20 to mid-life, central adiposity and height among 2871 prenatally exposed and 1352 unexposed women between 23 and 52 years of age (median 41.5) at baseline in 1994. DES exposure status was confirmed by prenatal medical record review. We used multivariable log-binomial models to calculate risk ratios (RRs) for obesity in 2006, and linear regression to calculate mean differences in body mass index, weight gain, waist circumference and height. The adjusted RR for DES and obesity was 1.09 [95% confidence interval (CI): 0.97, 1.22], and RRs were 1.23 (CI: 1.07, 1.42) and 1.05 (CI: 0.91, 1.20) for low and high estimated total DES dose, respectively, compared with no exposure. DES-exposed women gained slightly more weight than unexposed women [mean difference, 0.70 kg (CI: -0.27, 1.66)]. This study suggests that prenatal DES exposure may be associated with a small increase in adult obesity.