Prenatal Arsenic Exposure And Developmental Behaviors In Infants At Age 6 Months:a Prospective Birth Cohort Study

ObjectivesTo investigate the prevalence of developmental delay of 6 months infants and the levels of arsenic exposure in pregnant women were measured,and further examine the effect of being As exposure during pregnancy on developmental behaviors of infants at age 6 months.MethodsThis study was based on Ma’anshan Birth Cohort Study（MABC）,and all the subjects were set up in the Maternal and Child Health（MCH）Center in Ma’anshan city for the first time.The medical examination and delivery,consultation and voluntary written consent of the hospital were included in the study.Collection of pregnant women age,height and weight and other demographic data;neonatal gestational age,birth weight,length,head and other information was collected.The levels of arsenic in cord blood and first trimester and second trimester were divided into four groups according to the quartile,and the concentration of <P₂₅ was used as the reference group.Body measurements such as body length and body weight were performed at the time of 6-month-old infants.The Ages and Stages Questionnaires of China（ASQ-C）was used to evaluate the developmental status of 6-month-old infants.The evaluation criteria of each domain were grouped according to the sum and standard deviation of the six items in each domain.The scores < （?）-2s as severe developmental delay,the scores were between < （?）-2s and < （?）-s as mild developmental delay,the scores ≥ （?）-s as normal development.A total of 3 474 pregnant women were enrolled in our study.Among them,162 pregnant women had their pregnancy ended before delivery,and 39 twins were excluded from the study.There were 134 pregnant women who were under 37 weeks of gestation,520 pregnant women with gestational diabetes mellitus,gestational hypertension,preeclampsia,chronic hypertension with pregnancy,a total of 2 619 singleton live births.Exclusion of lost and refused,376 infants did not complete ASQ-C,Of which 198 pregnant women were missing blood samples in the first trimester,114 cases of maternal blood loss in the second trimester,339 samples of cord blood loss.So this analysis of the sample number of early pregnancy 2 145 cases,2 229 cases of mid-pregnancy,cord blood 2 004 cases.One-way analysis of variance（ANOVA）and χ² test were used to compare continuous and categorical variables in groups,respectively.The Nonparametric Kruskal-Wallis H（K-H）was used to compare the difference of the scores of the ASQ domain in the first trimester,the second trimester and the cord blood respectively.The Univariate and multivariate logistic regression effects of different concentrations of arsenic in the first trimester,the second trimester and the cord blood on developmental behavior of 6 months infants.ResultsThe highest concentration of arsenic in cord blood,pregnant women followed by the second trimester,the detection rate of blood arsenic was 100% in the first and second,and 99.9% in cord blood.The prevalence of delayed development of 5 ASQ-C domains was 14.8% for communication（CM）,17.0% for gross motor（GM）,13.6% for fine motor（FM）,14.0% for problem solving（CG）,and 16.8% for personal-social（PS）in the first trimester,and the prevalence of delayed development of 5 ASQ-C domains was 14.9% for communication（CM）,17.1% for gross motor（GM）,14.1% for fine motor（FM）,14.2% for problem solving（CG）,17.0% for personal-social（PS）in the second trimester,and the prevalence of delayed development of 5 ASQ-C domains was 14.9% for communication（CM）,17.3% for gross motor（GM）,14.4% for fine motor（FM）,14.4% for problem solving（CG）,17.2% for personal-social（PS）in the cord blood.The concentrations of arsenic exposure during each trimester were divided into four different levels of exposure according to the quartile.There were significant differences in the scores of the ASQ-C scores between the exposure to arsenic except communication（CM）in the first trimester;there was no significant difference between the arsenic exposure except for problem solving（CG）in the second trimester;there were significant differences in the scores of arsenic exposure between the problem solving（CG）and personal-social（PS）,and there was no significant difference among the other three functional areas.The arsenic concentration of <P₂₅ was used as the reference group,the results of single factor Ordinal logistic regression analysis showed that the level of arsenic exposure in the first pregnancy increased the risk of the personal-social（PS）domain delay of 6 months infants,RR values 1.476（95%CI: 1.078².020）.The level of arsenic exposure in the cord blood increased the risk of problem solving（CG）and personal-social（PS）of 6 months infants,RR values 1.461（95%CI: 1.026².081）,1.517（95%CI: 1.078².138）、1.763（95%CI: 1.260².467）,respectively.After controlling for the demographic information of pregnant women and the various stages of pregnant women BMI,newborns gestational age,weight and other basic information,the information of weight,length and head circumference dat for 6 months infant We only found that the level of arsenic exposure in the cord blood increased the risk of problem solving（CG）and personal-social（PS）of 6 months infants,RR values 1.514（95%CI: 1.015².259）,1.679（95%CI: 1.140².472）、1.714（95%CI: 1.169 2.514）,respectively.Multivariate logistic analysis of arsenic exposure in different gestational periods on ASQ-C in the same 6-month-old infants showed that elevated levels of arsenic in cord blood increased the risk of problem solving（CG）and personal-social（PS）of 6 months infants.ConclusionThe level of arsenic exposure in pregnant women during the first trimester and second trimester was not associated with the developmental behavior of infants at 6 months of age.The increased exposure to arsenic in cord blood increased the risk of developing abnormalities in the problem solving（CG）and personal-social（PS）domain.