Pharmacologic sex hormones in pregnancy in relation to offspring obesity

OBJECTIVE: To assess the association between in utero exposure to either diethylstilbestrol (DES) or an oral contraceptive in pregnancy and offspring obesity. METHODS: Using data from the Collaborative Perinatal Project (1959-1974), a multicenter prospective study of pregnant women and their offspring, we examined overweight or obesity among 34,419 children with height and weight data at age 7 years. Generalized linear models to estimate the adjusted odds ratio (aOR) for overweight or obesity (≥85th percentile) or obesity (≥95th percentile) in the offspring according to exposure during different months of pregnancy were used. RESULTS: Oral contraceptive use during pregnancy was positively associated with offspring overweight or obesity and obesity. The magnitude of association was strongest in the first 2 months of pregnancy for obesity (aOR 2.0, 95% CI: 1.1, 3.7). DES use was also associated with offspring overweight or obesity and obesity, with the association being strongest for exposure beginning between months 3 and 5 (e.g., for exposure beginning in months 3-4, the aOR for obesity was 2.8, 95% CI: 1.3, 6.3). CONCLUSIONS: Pharmacologic sex hormone use in pregnancy may be associated with childhood obesity. Whether contemporary, lower dose oral contraceptive formulations are similarly associated with increased risk of childhood obesity is unclear.