Serum levels of perfluoroalkyl compounds in human maternal and umbilical cord blood samples

Perfluoroalkyl compounds (PFCs) are end-stage metabolic products from industrial flourochemicals used in the manufacture of plastics, textiles, and electronics that are widely distributed in the environment. The objective of the present study was to quantify exposure to perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorodecanoic acid (PFDeA), perfluorohexane sulfonate (PFHxS), perfluoroheptanoic acid (PFHpA), and perfluorononanoic acid (PFNA) in serum samples collected from pregnant women and the umbilical cord at delivery. Pregnant women (n=101) presenting for second trimester ultrasound were recruited and PFC residue levels were quantified in maternal serum at 24-28 weeks of pregnancy, at delivery, and in umbilical cord blood (UCB; n=105) by liquid chromatography-mass spectrometry. Paired t-test and multiple regression analysis were performed to determine the relationship between the concentrations of each analyte at different sample collection time points. PFOA and PFOS were detectable in all serum samples analyzed including the UCB. PFOS serum levels (mean+/-S.D.) were significantly higher (p<0.001) in second trimester maternal serum (18.1+/-10.9 ng/mL) than maternal serum levels at delivery (16.2+/-10.4 ng/mL), which were higher than the levels found in UCB (7.3+/-5.8 ng/mL; p<0.001). PFHxS was quantifiable in 46/101 (45.5%) maternal and 21/105 (20%) UCB samples with a mean concentration of 4.05+/-12.3 and 5.05+/-12.9 ng/mL, respectively. There was no association between serum PFCs at any time point studied and birth weight. Taken together our data demonstrate that although there is widespread exposure to PFCs during development, these exposures do not affect birth weight.