Interaction Of Maternal Pre-pregancy Body Mass Index With Prenatal Bisphenol A Exposure And Obesity Measurement Index In Preschool Children:A Birth Cohort Study

ObjectivesWe estimated the independent association and interaction of bisphenol A exposure and pre-pregnancy body mass index with obesity measurement indicators such as upper arm circumference,upper arm sebum thickness,abdominal wall skin fold thickness in preschool children,and provide evidence-based evidence for women’s and children’s health care.MethodThe birth cohort study design was used in this study.From October 2008 to October 2010,pregnant women who had a card check-up at the Ma’anshan Maternal and Child Health Machine were recruited.In the early,middle and late stages of pregnancy,a self-made"Maternal and Child Health Record Form"was used to survey pregnant women.The maternity examinations,delivery and birth outcomes of pregnant women copied from the hospital electronic medical system After excluding 66 twin pregnancy,92 spontaneous abortions,55 stillbirths and stillbirths,and 202 missing followers,a total of 4,669 single-birth live births entered the child follow-up cohort.They were followed regularly after birth,every3 months before the age of 1 and every six months after the age of 1 year.In 2014,the physical examination of children in cohorts of various kindergartens in the city on June 1st collected obesity measurement indicators.From December 2012 to January 2014,BPA concentrations were measured in the serum of 1,783 pregnant women in the chronological order of blood sample collection.Excluding 14missing data on obesity indicators for preschool children（nine cases of upper arm circumference;five cases of BMI missing）,a total of 1,769 mother-to-newborn pairs were included in this study.The HPLC-MS/MS method was used to detect the serum free BPA concentration in pregnant women during pregnancy.The research team compiled the"Preschool Children’s Health and Behavior Record Form"to collect child-related characteristics information.The children were examined on June 1,2014.,Recording physical measurements such as upper arm circumference,upper arm skin fold thickness,and abdominal wall skin fold thickness of preschool children.The Z-score method recommended by the World Health Organization（WHO）was used to evaluate the BMI of preschool children.The median and quartiles were used to describe the general distribution of serum free BPA.The serum BPA concentration of pregnant women was divided into low(<P₂₅),medium(P₂₅～P₇₅),and high(>P₇₅)exposure groups according to the three-point method of P₂₅ and P₇₅.The mother’s body mass index（BMI）before pregnancy was divided into three groups:weight loss（<18.5kg/m²）,normal（18.5-23.9 kg/m²）,and overweight（≥24.0kg/m²）.Chi-square test（χ²）was used to compare the distribution of serum free BPA concentrations in different characteristics of mothers during pregnancy.Z test and one-way analysis of variance were used to compare the differences in the distribution of the upper arm circumference,upper arm skin fold thickness,abdominal wall skin fold thickness,and age-specific BMI score of preschool children with different characteristics.After controlling confounding factors such as maternal age and education,a polynomial linear regression model was used to analyze the association of serum free BPA during pregnancy,maternal BMI before pregnancy and obesity measures in preschool children,and explore the interaction between BPA exposure during pregnancy and BMI before pregnancy.ResultThe BPA concentration range of pregnant women detected in this study ranged from 0.001 to 20.7181ng/ml,and the median BPA concentration was 0.2372ng/ml.After controlling for confounding factors,a multivariate linear regression model showed that compared with the BPA low exposure group,the BPA exposure group（?=-0.087,95%CI:-0.492,-0.100）and the high exposure group can reduce preschool children.Upper arm circumference（?=-0.087,95%CI:-0.492,-0.100）;compared with the BPA low-exposure group,the exposed group of BPA can reduce the thickness of abdominal wall skin folds in preschool children（?=-0.079,95%CI:-0.1.01,-0.165）.After controlling for confounding factors,a multivariate linear regression model showed that,compared with the wasting group,the mothers before pregnancy and the normal BMI group and the overweight/obesity group can increase the upper arm circumference of preschool children（normal group:?=0.186,95%CI:0.492,0.869;overweight/obese group:?=0.145,95%CI:0.637,1.350）,upper arm skin fold thickness（normal group:?=0.134,95%CI:0.655,1.489;overweight/obese group:?=0.067,95%CI:0.217,1.790）,abdominal wall skinfold thickness（normal group:?=0.113,95%CI:0.522,1.428;overweight/obese group:?=0.094,95%CI:0.676,2.392）.After controlling for confounding factors,compared with the wasted group,the undetected normal group increased the upper arm skin fold thickness of preschool children（?=0.119,95%CI:0.083～2.828）,and the undiluted group decreased the age of preschool children.Do not have a BMIz score（?=-0.053,95%CI:-0.636,-0.006）.ConclusionStudies have shown that BPA exposure during pregnancy is negatively correlated with obesity measures in preschool children,and overweight/obesity before pregnancy is positively correlated with obesity measures in preschool children.There is an antagonistic effect between the two.At present,the results of studies on BPA exposure during pregnancy and the association between pre-pregnancy BMI and offspring obesity measurement are still controversial,and large samples will be needed in the future.Multi-center prospective cohort studies and animal experiments will be explored.