Study Of The Effects Of Single And Multiple Perfluorinated Compound Exposure During Pregnancy On Neonatal Growth Indicators

Objective:Perfluoroalkyl Compounds(PFCs)are persistent organic pollutants that are widely found in the environment and in living organisms,and are widely used in textiles,fire protection,food packaging and non-stick coatings due to their hydrophobic,grease and oil-repellent properties.PFCs can enter the cord blood through the placenta and,because of their hormone-like effects on endocrine metabolism,can affect thyroid hormone and lipocalin levels in cord blood,which may have an impact on neonatal birth outcomes.The levels of PFCs in cord blood reflect the outcome of prenatal exposure.Therefore,in this study,the levels of PFCs in cord blood samples were measured to understand the levels of various PFCs in the cord blood of newborns in Shenyang,to investigate the effects of single PFCs and mixtures of PFCs on neonatal birth outcomes and the importance of each PFC,and to provide a scientific basis for the formulation of neonatal health policies.Methods:In this cross-sectional study,175 maternal and neonatal pairs delivered by natural birth and cesarean section at Shengjing Hospital in Shenyang from 2017 to 2020were used to obtain basic maternal information,neonatal cord blood samples and birth physical indicators.The levels of eight perfluorinated compounds in cord blood were obtained by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS).Due to the skewed distribution of PFCs concentrations in cord blood,median and quartiles were used to describe PFCs levels and the resulting concentrations were lg-transformed before further statistical analysis was performed.Spearman correlation analysis was used to describe the correlation between individual PFCs.Multiple linear regression was used to analyse the linear association between single PFC exposure and neonatal birth outcomes.Bayesian Kernel Machine Regression(BKMR)was used to explore the non-linear association between individual PFCs and neonatal birth outcomes,the joint effect of mixtures of multiple PFCs on neonatal birth outcomes,and the significance of individual PFCs in the effect on neonatal birth outcomes.Results:A total of 14 perfluorinated compounds were detected in this study,of which 8were detected at a rate of greater than 50%,namely Perfluorobutanoic Acid(PFBA),L-Perfluorohexanesulfonic Acid(L-PFHx S),Perfluorooctanoic Acid(PFOA),Perfluoronontanoic Acid(PFNA),Perfluorooctane Sulfonate(PFOS),Perfluorodecanoic Acid(PFDA),Perfluoroundecanooic Acid(PFUd A)and Perfluorotridecanoate Acid(PFTr DA).Their median concentrations of 0.13、0.20、0.92、0.15、0.36、0.11、0.09、0.14 ng/m L,respectively.Spearman’s correlation analysis showed a significant positive correlation between the majority of PFCs.The results of the multiple linear regression model showed that each lg unit increase in PFOS concentration decreased birth weight,birth length and birth head circumference by 465.31 g(P=0.025),5.27 cm(P<0.001)and 2.22 cm(P=0.009)for males,3.13 cm(P=0.005)for all-sex birth head circumference and 4.58 cm(P=0.038)for females.A one lg unit increase in PFUd A concentration was associated with a 5.99 kg/m~3 decrease in all-sex ponderal index(P=0.025),a 7.44 cm increase in birth length for males(P=0.003)and a 14.16 kg/m~3 decrease in ponderal index(P<0.001).The results of the univariate cross-sectional Bayesian kernel function regression(BKMR)showed a linear relationship between all eight PFCs and neonatal outcome,with no non-linear relationships.The results for the overall effect of the BKMR mixture showed that when all PFCs were at or above the 60th percentile compared to the50th percentile,the overall effect of the mixture tended to decrease linearly with birth weight and birth head circumference for male infants and increase linearly with gestational age for all-sex and female infants and birth weight for female infants.The results of the BKMR univariate effects showed a positive effect of PFBA on gestational age in female infants,a negative effect of PFOS on birth weight in male infants,a significant negative effect of PFOS on birth length in male infants,a significant negative effect of PFOS on both all-sex and male infant birth head circumference,and a negative effect of PFUd A on the all-sex ponderal index and a significant negative effect on the ponderal index in male infants.BKMR results showed that the posterior inclusion probability(PIP)of PFOS was greater than 0.5 for all sexes for birth head circumference and ponderal index,and greater than 0.5 for birth weight,birth length,birth head circumference and ponderal index for male infants,but equal to 0.5 for birth weight for female infants only.Conclusion:PFOS was a significant factor associated with low birth height and low birth head circumference in this study,and PFUd A has a negative effect on the ponderal index at birth in male infants.PFC compounds in male infants had a negative effect on birth weight and birth head circumference.The adverse effects of perfluorinated compounds on neonatal growth indicators in this study were more pronounced in male infants.