Placental 11ß-Hydroxysteroid dehydrogenase type 2 expression: Correlations with birth weight and placental metal concentrations.

INTRODUCTION: Infants born below 2500 g are classified as low birth weight. Excess in utero exposure to cortisol has been linked to restricted fetal growth. Placental production of 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) inactivates cortisol before passage into the fetus. The present study tested the hypothesis that placental 11ß-HSD2 expression is positively correlated with an individualized birth weight centile and raw birth weight, and examines the relationship between metal concentrations in placental tissue and 11ß-HSD2 expression. METHODS: Placentae from 191 births were collected and samples preserved to maintain mRNA profile. Placental 11ß-HSD2 expression was measured via qRT-PCR. Addition samples were collected from placental tissues and uniformly dried in order to quantify 18 metals via ICP-MS (n = 160). RESULTS: A significant, positive correlation between 11ß-HSD2 expression and individualized birth weight centile (p = 0.0321) and birth weight (p = 0.0243) was found. Additionally, maternal age and gestational age were positivity correlated with each other (p = 0.0321). Birth weight was significantly different with race, marital status, education and maternal tobacco use. Four metals (Co, Mn, Ni, Zn) demonstrated significant positive correlations (p < 0.05) with 11ß-HSD2 expression. Sex specific differences were found; Co, Cu, Fe, Zn, and Ni were positively correlated with 11ß-HSD2 expression in males only, no significant correlations were found in the female only sample. CONCLUSION: These data indicate that the growth potential of a fetus is related to the 11ß-HSD2 expression in the placenta, and that 11ß-HSD2 expression is related to the trace metals status of the mother.

Placental concentrations of bisphenol A and birth weight from births in the Southeastern U.S.

INTRODUCTION: Bisphenol A (BPA) is a weakly estrogenic compound that has been detected in a wide variety of food products and biological matrices (saliva, blood, urine, etc). Despite the potential risk of human exposure to BPA, little information exists concerning maternal and fetal exposure to BPA during pregnancy. The aim of this study is to evaluate the correlation between placental BPA concentration, infant birth weight and calculated birth weight centile, and several other maternal and infant parameters. METHODS: Placental sample were collected from 200 subjects. BPA levels were measured by isotope dilution GC-MS. Additional maternal and infant data were gathered from medical charts and were potential correlates with placental BPA levels. RESULTS: Placental BPA concentrations ranged from 4.4 ng/g to 273.9 ng/g in oven-dried tissue (average 103.4 ± 61.8 ng/g). There was a significant negative correlation between calculated birth weight centile and levels of placental BPA (p < 0.05). Low birth weight and small for gestational age infants also had significantly greater placental BPA concentrations as compared to normal weight infants and average/large for gestational age infants. Infants born to African American mothers also had greater placental BPA concentrations as compared to infants born to Hispanic mothers. DISCUSSION: Placental BPA concentrations are correlated with the growth potential of the fetus and may play a role in reduced fetal growth.