Correlation between exposure to polycyclic aromatic hydrocarbons during pregnancy and placental mitochondrial DNA copy number / 预防医学

ABSTRACT

Objective@#To examine the correlation between exposure to polycyclic aromatic hydrocarbons ( PAHs ) and placental mitochondrial DNA ( mtDNA ) copy number among pregnant women, so as to provide the evidence for evaluation of potential effects of PAHs exposure during pregnancy on offspring health.@*Methods@#A total of 200 pregnant women delivered at a tertiary hospital in Urumqi City during the period from January to October 2019, and their newborns were recruited, and grouped according to the time of delivery, including the heating group [delivery during the heating period ( from January to April ) ] and the non-heating group [delivery during the non-heating period (from July to October) ]. Subjects'age, ethnicity, educational level and type of home heating were collected, and the total concentration of 16 PAHs was determined in the blood samples of pregnant women and their babies using gas chromatography-mass spectrometry. Placental DNA was extracted, and placental mtDNA copy number was measured using real-time fluorescence quantitative PCR assay. In addition, the correlation between PAHs concentration and placental mtDNA copy number was examined using the Spearman rank correlation analysis.@*Results@#There were 100 subjects in the heating group, which had a median age of 29 ( interquartile range, 3 ) years and had a mean gestational age of ( 275.06±0.72 ) days, and there were 100 subjects in the non-heating group, which had a median age of 29 ( interquartile range, 4 ) years and had a mean gestational age of ( 276.82±0.66 ) days. The total concentration of PAHs in the blood of pregnant women [15.71 (4.30) vs. 12.98 (5.49) μg/L; P<0.05 ], the total concentration of PAHs in neonatal blood [ 14.29 (4.25) vs. 11.24 (5.09) μg/L; P<0.05 ] and the placental mtDNA copy number [4.67 (1.18) vs. 4.51 (0.62); P<0.05] were all higher in the heating group than in the non-heating group. Spearman rank correlation analysis revealed that the total concentration of PAHs in the blood of pregnant women and neonates was positively correlated with placental mtDNA copy number ( rs=0.240, P=0.001; rs=0.273, P<0.001 ), and the total concentration of PAHs in the blood of pregnant women was positively correlated with the placental mtDNA copy number in the heating group ( rs=0.245, P=0.014 ), while the PAHs concentration in the neonatal blood was positively correlated with the placental mtDNA copy number in the non-heating group ( rs=0.292, P=0.003 ).@*Conclusions@#Exposure to PAHs positively correlates with placental mtDNA copy number among pregnant women, and there is a correlation between maternal exposure to PAHs and neonatal oxidative stress.