Background Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are widely used in industrial production and the manufacture of consumer products and are reported to have been detected in pregnant women's blood, placenta, and fetal cord blood. However, data on PFASs concentrations in pregnant women are inconsistent.
Objective This study is designed to measure PFASs concentrations in peripheral blood in pregnant women and evaluate sociodemographic and dietary factors as potential determinants of PFASs concentrations.
Methods The present study was based on the Jiashan Birth Cohort from September 2016 to April 2018. Maternal peripheral venous blood samples (n=942) were collected from 942 pregnant women during prenatal examination at 16-24 weeks of pregnancy, and were analyzed for 13 PFASs using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). A structured questionnaire was used to investigate the social demographic characteristics, lifestyle, health status, dietary style, and exposure history of environmental pollutants during pregnancy. Multiple linear regression was used to examine the associations of ln-transformed PFASs concentrations with maternal sociodemographics, lifestyles, and dietary factors. The β values and 95% confidence intervals (CI) of factors associated with PFASs were calculated, and the log transformed estimates indicated the geometric mean ratio (GM ratio) of PFASs associated with per unit change of independent variables.
Results A total of 11 PFASs were detected in the peripheral blood of pregnant women, including perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluoroundecanoic acid (PFUdA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroheptanoic acid (PFHpA), perfluorododecanoic acid (PFDoA), perfluorotridecanoic acid (PFTrDA), perfluorotetradecanoic acid (PFTeDA), and perfluorohexanoic acid (PFHxA), of which the detection rates of former 9 PFASs were more than 90%. Perfluorodecane sulfonate (PFDS) and perfluorhecadecanoic acid (PFHxDA) were not detected in the present study. The median concentration of total PFASs was 37.95 μg·L-1. Among selected PFASs, the median concentration of PFOA was the highest (11.99 μg·L-1), followed by PFOS, PFHxS, PFDA, PFUdA, PFNA, PFDoA, PFTrDA, and PFHpA. Varing degrees of correlations were shown among the concentrations of PFOS, PFHxS, PFOA, PFDA, PFNA, PFHpA, PFUdA, PFDoA, and PFTrDA (r=0.35-0.94); PFDA and PFUdA were most strongly correlated (r=0.94), followed by PFOS and PFDA (r=0.90). PFASs concentrations increased 1.42 times (95% CI: 1.05-1.93) to 10.06 times (95% CI: 5.01-20.20) in pregnant women who were older, well educated, and with higher pre-pregnancy body mass index (BMI). The concentration of PFOA in parous women was lower than that of nulliparous women (GM ratio=0.73, 95% CI: 0.57-0.93). The concentrations of some PFASs in pregnant women with a higher intake frequency of fish, eggs, animal offal, or soy products during pregnancy increased by 1.56 times (95% CI: 1.01-2.43) to 5.28 times (95% CI: 2.40-11.58), while concentration of PFOA in pregnant women with a higher intake frequency of whole grainswas lower (GM ratio=0.67, 95%CI: 0.46-0.99), and the concentrations of PFASs in pregnant women who mainly drank bottled water were lower (GM ratio: 0.15-0.50).
Conclusion Pregnant women in Jiashan are widely exposed to PFASs. Besides PFOA and PFOS, the concentrations of some emerging PFASs are also higher in pregnant women's peripheral blood. Maternal age, pre-pregnancy BMI, education level, parity, and dietary factors may affect the levels of PFASs exposure.
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