#19 Associations of maternal and umbilical cord hormone concentrations with maternal, gestational and neonatal factors

Abstract

PURPOSE: High birth weight has been associated with adult breast and prostate cancer risk in epidemiologic studies and is hypothesized to be mediated through higher in utero estrogen concentrations. This hypothesis is based on maternal estrogen concen- trations, while limited data exist on the fetal circulation. METHODS: Concentrations of androstenedione, testosterone, estradiol, estriol, estrone, dehydroepiandrosterone (DHEA) and DHEA-Sulfate (DHEAS) were measured in maternal and mixed umbilical cord sera from 86 normal, singleton pregnancies. Maternal samples were collected at admission for labor and delivery. RESULTS: In the maternal sera, only estriol was positively correlated with gestational age (Spearman r = 0.35 ) and birth size including, birth weight (r = 0.36), length (r = 0.30) and head circumference (r = 0.25). Cord DHEAS concentrations, but none of the other hormones, were positively correlated with gestational age (r = 0.32), birth weight (r = 0.34), birth length (r = 0.41) and head circumference (r = 0.24). In linear regression analyses, maternal estriol and cord DHEAS predicted birth weight after adjustment for gestational age. No other hormones were independently associated with birth weight. Inspection of mean hormone levels by strata of birth weight (<2500, 2500–3499, 3500+), however, revealed nonlinear relations with the lowest birth weight babies having the lowest maternal estriol and cord DHEAS and no consistent pattern in the upper two categories. CONCLUSION: These data show an association between hormone concentrations and birth weight, however, the hormones involved and their patterns of association differ between the fetal and maternal results. In addition, these data are not consistent with the hypothesis that higher estrogen concentrations in high birth weight babies mediate the positive association with breast cancer risk observed in epidemiologic studies.