Dietary exposure level of to perfluorinated compounds and its relationship with perinatal adverse events in pregnant women in Xuhui District of Shanghai

Background Perfluorinated compounds (PFCs) are persistent organic pollutants. Dietary exposure to PFCs among pregnant women may lead to elevated risks of adverse events during pregnancy and postpartum depression.

Objective To estimate potential risk of dietary exposure to PFCs among pregnant women in Xuhui District, Shanghai, and the relationship between dietary PFCs exposure and risks of adverse events during pregnancy and postpartum depression.

Methods This study was a small cohort study which recruited women residing in Xuhui District from July 2017 to September 2018. All information was collected through questionnaires by trained investigators. Basic information and dietary information were collected at the time of inclusion, where the dietary information was obtained through the Food Frequency Questionnaire (FFQ). A follow-up visit was conducted within 42 d after delivery to collect the occurrence of adverse events during pregnancy and postpartum depression. According to the results of dietary survey, sampling and PFCs level testing were conducted on commercially available staple foods, poultry and livestock meat, aquatic products, vegetables, milk and dairy products, eggs, etc. The food sampling points covered all subdistricts in Xuhui District, including farmers' markets, supermarkets, convenience stores, and shops. Daily exposure level and hazard ratio (HR) of PFCs per capita were calculated according to the dietary survey and laboratory testing. Logistic regression was used to estimate the relationship between PFCs exposure and the risks of adverse events during pregnancy and postpartum depression. The levels of PFCs exposure were further divided into 4 groups according to interquartile range, and OR and P_trend value were calculated respectively.

Results A total of 345 pregnant women were recruited in this study, whose average age was (29.61±4.92) years. Among them, 26.37% subjects reported at least one adverse event during pregnancy, and 30.14% subjects reported an Edinburgh Postnatal Depression Scale (EPDS) score ≥12. A total of 132 food samples were collected and tested, and PFCs were positive mainly in milk and dairy products, poultry meat, livestock meat, eggs, fresh water products, and sea water products. The PFCs positive rate in fresh water products was the highest, reaching 100%. The average concentration of PFCs in the positive samples was 0.018-2.10 μg·kg⁻¹. The HR of PFCs was 4.44. A higher risk of postpartum depression was found along with a higher perfluorooctane sulfonate (PFOS) exposure level (P_trend=0.02).

Conclusion Dietary PFCs exposure may pose a health risk to pregnant women. The study findings suggest that decreasing the intake of freshwater products might help reduce the risk of PFCs exposure among pregnant women in Xuhui district, Shanghai.