Bisphenol-A (BPA), BPA Glucuronide, and BPA Sulfate in Midgestation Umbilical Cord Serum in a Northern and Central California Population

Bisphenol-A (BPA) is an endocrine disrupting chemical used in numerous consumer products, resulting in universal exposure in the United States. Prenatal exposure to BPA is associated with numerous reproductive and developmental effects in animals. However, little is known about human fetal exposure or metabolism of BPA during mid-gestation. In the present study, we present a new liquid chromatography-tandem mass spectrometry method to directly measure concentrations of BPA and two predominant metabolic conjugates – BPA glucuronide and BPA sulfate – in umbilical cord serum collected from elective 2(nd) trimester pregnancy terminations. We detected at least one form of BPA in all umbilical cord serum samples: BPA (GM 0.16; range <LOD-52.26 ng/mL), BPA glucuronide (GM 0.14; range <LOD-5.41 ng/mL) and BPA sulfate (GM 0.32; range <LOD-12.65 ng/mL). Levels of BPA ranged from less than 1/100(th) to over 400 times higher than levels of BPA in conjugated form. Although levels of BPA in conjugated form exceeded BPA levels in about 3/4 of the samples, BPA levels were higher in samples with Total BPA above the median. Our findings suggest universal fetal exposure to BPA in our study population, with some at relatively high levels, and we provide the first evidence of detectable BPA sulfate in mid-gestation fetuses