Association Of Maternal Body Mass Index With Birth Defects In Offspring

BackgroundsOverweight and obesity have become a major public health problem worldwide.The Body Mass Index(BMI)of women of reproductive age has a significant impact on maternal and infant health at birth,with underweight mothers having an increased risk of underweight babies and preterm births,and overweight and obese mothers having an increased risk of adverse pregnancy outcomes such as cesarean delivery,gestational diabetes,gestational hypertension,labor induction,postpartum hemorrhage,preeclampsia,and premature rupture of membranes.A growing body of research findings suggests that unhealthy preconception or early pregnancy BMI in women of reproductive age is strongly associated with the occurrence of birth defects,but evidence based on Chinese populations is lacking.The aim of this study was to systematically analyze the association between prepregnancy and early pregnancy BMI and birth defects in offspring based on a large-scale population analysis of the distribution of pre-pregnancy BMI in Chinese women of reproductive age in recent years,to explore the appropriate pre-pregnancy and early pregnancy BMI ranges for Chinese women of reproductive age,and to provide a data base and scientific evidence for pre-pregnancy-pregnancy weight management and prevention and treatment of birth defects in Chinese women of reproductive age.MethodsThe first part of this study included 9220,664 women of reproductive age who participated in the national free preconception eugenic health screening program in 2013 and 2019,analyzed the prevalence of underweight,overweight and obesity,calculated the age standardization rate using the 2010 national census data,and analyzed the related influencing factors using Logistic regression.The second part of this study was based on the China Preconception-Pregnancy-Birth Defects Cohort,a retrospective cohort study that included 67,603 study subjects who participated in preconception eugenic health screening from 2010 to 2019 and had complete information registered in the National Birth Defects Surveillance,respectively,and analyzed the association between maternal preconception BMI and offspring birth defects using logistic regression models by restrictive cubic spline to explore the relationship between maternal pre-pregnancy BMI and exposure response to birth defects in offspring,and to further assess the effect of maternal pre-pregnancy BMI on birth defects in offspring in different subgroups through subgroup analysis.The third part of this study included 24,861 study subjects with perfect information registration who participated in the prospective cohort study from 2018 to 2022,and explored the association between maternal early pregnancy BMI and offspring birth defects using logistic regression models,respectively,and explored the relationship between maternal early pregnancy BMI and offspring birth defects in terms of exposure response through restricted cubic splines,and further assessed the effect of different subgroups through subgroup analysis The effect of maternal BMI in early pregnancy on offspring birth defects was further assessed by subgroup analysis.Results1.the underweight rate of Chinese women of reproductive age decreased from 8.93%in 2013 to 7.47%in 2019;the overweight rate of women of reproductive age increased from 18.62%in 2013 to 21.05%in 2019;the obesity rate increased from 4.54%in 2013 to 6.08%in 2019.Low age and high educational level are risk factors for underweight,advanced age,farmers,and ethnic minorities are risk factors for overweight and obesity,while vegetarian habits,smoking or passive smoking may increase the risk of underweight or overweight and obesity.2.Of the 67,603 study subjects included in the study of the association between maternal pre-pregnancy BMI and offspring birth defects,a total of 1,192 children with birth defects were monitored,and the total incidence of birth defects was 176.32 per 10,000.Low maternal pre-pregnancy weight was significantly associated with the risk of reproductive birth defects in offspring with an adjusted OR of 1.90(95%CI:1.09 to 3.30).Maternal pre-pregnancy obesity was significantly associated with the risk of cleft lip and palate in the offspring with an adjusted OR of 4.30(95%CI:1.47 to 12.57).3.Of the 24,861 study subjects included in the study of the association between maternal early pregnancy BMI and offspring birth defects,507 children with birth defects were monitored and the total incidence of birth defects was 203.93 per 10,000.Maternal underweight in early pregnancy was significantly associated with the risk of congenital heart disease in offspring with an adjusted OR of 1.41(95%CI:1.01 to 1.97).Maternal obesity in early pregnancy was significantly associated with the risk of congenital heart disease in the offspring,with an adjusted OR of 2.64(95%CI:1.43 to 4.86).Conclusions1.In recent years,Chinese women of reproductive age face the dual challenge of malnutrition and overnutrition before pregnancy.Although underweight in women of reproductive age in China has shown a decreasing trend,it is still prevalent in some populations,and overweight and obesity have shown a significant increasing trend,which has become one of the important public health problems affecting maternal and child health.2.Low pre-pregnancy weight of mothers is significantly associated with the risk of reproductive organ birth defects in the offspring,while pre-pregnancy obesity is significantly associated with the risk of cleft lip and palate in the offspring.It is recommended to scientifically manage the pre-pregnancy BMI level of women of reproductive age to improve maternal health and promote optimal fertility.3.Low maternal weight in early pregnancy is significantly associated with the risk of congenital heart disease in offspring,while maternal obesity in early pregnancy is significantly associated with the risk of congenital heart disease in offspring.It is urgent to develop practical and effective weight management measures during pregnancy.