Prenanal PAHs Exposure,5-hmC In Umbilical Cord Blood And Neonatal Neurobehavioral Development

Objective:1.To explore the associations between prenanal PAHs exposure,5-hmC and neonatal neurobehavioral development.2.To explore whether 5-hydroxymethyl cytosine is a mediator of the association between prenanal PAHs exposure and neonatal neurobehavioral development.Methods:A total of 201 mother-newborn pairs were recruited in some hospital in Taiyuan.The mothers provided informed consent for themselves and their children.Questionnaire was administered by a trained interviewer during the last trimester of pregnancy.The PAHs metabolites?OH-PAHs?levels in urine samples were analyzed using ultrasensitive performance liquid chromato-graphytandem mass spectrometry?UPLC-MS/MS?.The total PAHs metabolites was dichotomized at the fourth quartile(P₂₅,P₇₅)to obtain a measure of low,medium and high exposure.The level of 5-hydroxymethyl cytosine?5-hmC?was analyzed using enzyme-linked immunosorbent assay?ELISA?.Neonatal behavioral neurological assessment?NBNA?was used to evaluate Neonatal neuro-behavioral development.Results:1.The levels of 2-hydroxynaphthalene,1-hydroxynaphthalene,3-hydoxyfluorene,2-hydoxyfluorene,2-hydroxyphenanthrene,9-hydroxyphenanthrene,1-hydroxyphenant-hrene,1-hydroxypyrene and total PAHs metabolites adjusted by urine specific gravity were 0.000⁰.556,0.000⁰.198,0.001⁰.183,0.000⁰.773,0.000⁰.586,0.000⁰.314,0.000⁰.301,0.001⁰.628,0.029⁰.967 ng/mL,respectively.2.Behavior scores of the three groups differed significantly?P<0.05?and behavior scores was lower in high exposure group than that in low exposure groups.There were no significant differences among low,medium and high exposure groups for passive tone,active tone scores,primary reflexes,general assessment scores and total NBNA scores?P>0.05?.3.5-hmC level in umbilical cord blood of the three groups differed significantly?P<0.05?and 5-hmC level was higher in high exposure group than that in low exposure group.4.Inmultiplelinearregression,PAHswasassociatedwithneonatal neurobehavioral development and 5-hm C?P<0.05?.5-hmC was associated with neonatal neurobehavioral development?P<0.05?.5.In multiple linear regression,3-hydoxyfluorene,2-hydoxyfluorene and total PAHs metabolites were the main influencing factor on neonatal neurobehavioral development?P<0.05?.6.In bootstrapping test,there was no significant mediating effect with the interval?LLCI=-0.3869,ULCI=0.0183?or?LLCI=-0.3063,ULCI=0.0608?.Conclusions:1.Prenatal PAHs exposure could adversely affect neonatal neurobehavioral development.2.In our study,the adverse effects of prenatal exposure to PAHs on neonatal neurobehavioral development did not appear to be directly mediated by altered 5-hmC.