Abstract
BACKGROUND: Birth characteristics and adult hormone concentrations influence breast cancer risk, but little is known about the influence of birth characteristics on hormone concentrations, particularly during adolescence. METHODS: We evaluated the association of birth characteristics (birth weight, birth length, and gestational age) with serum sex hormone concentrations during late childhood and adolescence in 278 female participants of the Dietary Intervention Study in Children. Repeated measures analysis of variance models were used to assess the relationships of birth characteristics and serum estrogens and androgens at five different time points over a mean period of 7 years. RESULTS: In analyses that did not take into account time from blood draw until menarche, birth weight was inversely associated with pre-menarche concentrations of estradiol, estrone sulfate, androstenedione, testosterone, and dehydroepiandrosterone sulfate (DHEAS). In the post-menarche analyses, birth weight was not significantly associated with concentration of any of the hormones under investigation. Birth length and gestational age were not associated with hormone concentrations before or after menarche. CONCLUSION: Birth weight is inversely associated with sex hormone concentrations before menarche in the model unadjusted for time from blood draw until menarche. IMPACT: The in utero environment has long-term influences on the hormonal milieu, which could potentially contribute to breast cancer risk.