Associations between maternal phenolic exposure and cord sex hormones in male newborns.

Abstract

Are maternal urinary phenol concentrations associated with cord steroid hormone levels and anogenital distance (AGD) in male newborns? High maternal urinary Bisphenol A (BPA) levels are associated with decreases in cord testosterone levels and the ratio of testosterone to estradiol in male newborns, but there was no significant association with AGD. Early life exposure to phenolic endocrine disrupting compounds (EDCs) is known to disrupt hormonal activities and affect reproductive development in males. However, studies on the health effects of prenatal human exposure are scarce. This was a cross-sectional study to investigate the association between maternal phenolic exposure and cord sex steroid hormones and AGD in male newborns. We recruited 100 mother-infant pairs from each of two hospitals, one in a polluted town (Guiyu) and the other in a cleaner town (Haojiang), from September 2010 to September 2011. One hundred and seventy eight maternal urine samples and 137 cord blood samples were available for quantification, thus 137 complete records entered into the final analysis. Of them, 77 pairs were from Guiyu, and 60 were from Haojiang. The chemical concentrations were determined by solid phase extraction and gas chromatography-mass spectrometry (SPE-GC-MS), and cord sex hormones were detected by radioimmunoassay (RIA). Neonatal anthropometric parameters including AGD were measured. Log2-transformed maternal urinary BPA concentration was negatively correlated with testosterone level and the ratio of testosterone to estradiol (T/E2) in male fetal cord blood after adjustment for potential confounders in linear regression models (βadjusted = -31.09 (95% CI, -53.07 to -9.11) and βadjusted = -0.08 (95% CI, -0.13 to -0.01), respectively). Moreover, compared with the lowest quartile group of BPA level, the highest group showed a significant decrease in testosterone level and T/E2 (βadjusted = -179.84 (95% CI, -333.45 to -26.24) and βadjusted = -0.37 (95% CI, -0.81 to 0.07), respectively). No significant associations between AGD or anogenital index (AGI, [AGI = AGD/birthweight (mm/kg)]) and phenolic EDCs or cord hormone levels were found. Results in the present study should be interpreted with caution because of its cross-sectional nature, small sample size and sampling time. Testosterone plays an important role in sex differentiation and normal development of the fetus and newborn, and the balance between testosterone and estradiol is thought an important mediator of prostate disease. Therefore, our findings may have important implications for human reproductive health. This work was supported by the National Natural Science Foundation of China (21377077) and Guangdong University Project for International Cooperation and Innovation Platform (2013gjhz0007). The authors declare they have no actual or potential competing financial interests.