Population-based Birth Defects And Abnormal Birthweight Cohort Study In Jiangsu

A birth cohort study is one in which babies are followed from birth and studied to determine why some babies go on to develop disease,whilst others remain healthy.The main aim of such kind of study is to discover as much as possible about how a person's inbuilt makeup(genome),and the environment they experienced during early life(in the womb and first few years of childhood),affect their health and ageing in later life.The birth cohort study was carried out as early as the beginning of the 20th century in developed countries.The Hertfordshire Cohort Study was the earliest birth cohort study in the world,which can be traced back to the small-scale birth cohort observation carried out in the South East of England Hertfordshire during the period 1911-1930,and followed by years 1931-1939 a more large-scale birth cohort of 39764 live births.Then a series of successful birth cohort study were carried out in the United States,Finland,India,Denmark and other developed countries,which constantly updated awareness of the disease.In 2000,a children's health projects bill was adopted in the United States,which authorized the United States National Institute of Child Health and Human Development Institute to carry out a national cohort study of childhood diseases and build a database of biological and environmental samples.So far,the study has been extended to the United States in over 100 cities.There were significant differences in the population genetics and behavior between Chinese and foreigner.In the past 30 years,socio-economic model and type of disease has changed dramatically in the mainland of China,especially in economically developed areas.Such kind of change makes the birth cohort study become extremely urgent and valuable in China.Unfortunately,the progress in the birth cohort study field in China is not satisfactory.For this reason,Jiangsu Population and Family Planning Committee established the Jiangsu Birth Defects and Child Development Cohort(JBC)during the period 2002 to 2005,and this was the first population-based large-scale birth cohort study in domestic.As a part of JBC,the present study aims to analyze the population incidence,distribution characteristics and the major risk factors of birth defects and abnormal birthweight in Jiangsu province by macro-epidemiology study methods,prospective cohort study and case control study.We also explored the long-term health consequence of abnormal birth weight later on in life.It is assumed that the research results will be of important theoretical and practical significance for screening residents at high risk,initiating strategies against birth defects and abnormal birthweight at both population and individual-level.PART 1Population-based birth defects cohort study in JiangsuObjectivesTo explore the method and feasibility of population-based birth defect surveillance,describe the epidemiological characteristics of birth defects in Jiangsu province,and to analyze the major influence factors of birth defects,so as to provide evidence for birth defect prevention and control.MethodsNinty-five communities were randomly selected as surveillance spots of birth defects by stratified cluster sampling in Jiangsu Province.A total of 27642 pregnant women and their offspring in the communities were investigated,the prospective collection of data from the time of selected to a follow-up period of 5.5-8 years.The collected data was analyzed to describe epidemiology characteristics and development trends of birth defects in Jiangsu.On the basis of the cohort study,we conducted a case control study to determine the risk factors of birth defects by multiple logistic regression analysis.Results1.A total of 27642 pregnant women and their offspring participated the study from December 2002 to May 2005.416 cases of various types of birth defects have been diagnosed by the end December 31,2010,the age-adjusted occurrence rate of birth defects in Jiangsu was 152.68/10000(95%CI:139.87-169.74/10000).2.The age-adjusted occurrence rate of birth defects in Subei,Suzhong and Sunan were 133.75/10000(95%CI:119.92-159.13/10000),162.68/10000(95%CI:134.07-197.07/10000)and 158.67/10000(95%CI:135.6-183.82/10000)respectively.Suzhong got first rank,Subei followed and Sunan got last rank.3.The age-adjusted occurrence rate of birth defects in urban and rural area were 87.01/10000(95%CI:62.05-116.99/10000)and 167.65/10000(95%CI:150.99-185.31/10000),respectively.4.The top four birth defects in Jiangsu were congenital malformations and deformation of the musculoskeletal system,congenital malformations in head and neck congenital heart disease and congenital malformations of the nervous system,according to the ICD10 classification.The age-adjusted occurrence rate were,27.52/10000(95%CI:21.67-34.40)?27.15/10000(95%CI:21.35-34.00)?20.26/10000(95%CI:15.62-26.71)and 17.98/10000(95%CI:13.33-23.81/10000)respectively.5.The multiple logistic regression analysis showed that maternal education level,maternal early pregnancy BMI and maternal career were independent factors.Compared with the primary or less group,mothers from junior school and high school or above group had a significantly decreased risk of delivering infants with birth defects,the OR value were 0.70(95%CI:0.50-0.99)and 0.60(95%Cl:0.38-0.93),respectively.Compared with the manual labor group,mothers who were engaged in mental work had a 0.54-fold(95%CI:0.30-0.96)risk of delivering infants with birth defects.Compared with women with normal weight(BMI 18.5-24),obese women(BMI?28)had a 1.68-fold(95%CI:1.09-2.63)risk of delivering infants with birth defects.Conclusions1.There are significant regional differences in the distribution of birth defects in Jiangsu.The top four birth defects in Jiangsu were congenital malformations and deformation of the musculoskeletal system,congenital malformations in head and neck congenital heart disease and congenital malformations of the nervous system.2.Maternal early pregnancy BMI ?28 had positive effects on delivering infants with birth defects.In contrast,pregnant women with a higher degree of education as well as being engaged in mental work had a negative effect.PART 2 Population-based abnormal birthweight cohort study in JiangsuObjectivesTo investigate the status of infant birth weight in Jiangsu province,analyze the related influencing factors of abnormal birth weight,and explore the long-term health consequences of neonates with abnormal birth weight,so as to provide a scientific evidence for abnormal birth weight prevention and control and the prediction of the long-term health consequences of neonates with abnormal birth weight.MethodsThe study design includes a retrospective population based cohort study and a nested case control study.Women with multiple pregnancies,preterm births,and absent information on birth weight at term were not included in present study.Cases with congenital malformations were excluded from the study.In total,21544 maternal and neonatal records were analyzed,and so allowing the calculation of the actual incidence of abnormal birth weight in the populations of Jiangsu Province.We carried out a comparison of related factors between newborns with abnormal birth weight and the control group using a case-control study design.Regression analysis was used to determine if in predicting abnormal birth weight significant contributions are provided by maternal and fetal characteristics.We also performed a comparison of the development in the beginning of childhood between the affected group and the control group from the birth cohort.Results1.The overall age-adjusted incidence of macrosomia in Jiangsu was 11.71%(95%CI:11.27-12.14%).The age-adjusted incidence in Sunan,Suzhong and Subei were 8.13%(95%CI:7.53-8.77%)?11.97%(95%CI:11.11-12.89%)and 14.96%(95%CI:14.19-15.75%)respectively.Subei got first rank,Suzhong followed and Sunan got last rank.2.The overall age-adjusted incidence of low birth weight in Jiangsu was 1.21%(95%CI:1.06-1.37%).The age-adjusted incidence in Sunan,Suzhong and Subei were 1.59%(95%CI:1.31-1.91%)?1.14%(95%CI:0.86-1.49%)and 1.02%(95%CI:0.80-1.29%),respectively.Sunan got first rank,Suzhong followed and Subei got last rank.3.The multiple logistic regression analysis of macrosomia showed that gestational age,maternal early pregnancy BMI and infant gender were included in the final model.The risk of delivering a neonatal macrosomia is increased by 1.03-fold(95%CI:1-1.04)for each additional one-year-old gestational age.Compared with women with normal weight(BMI 18.5-23.9),overweight(BMI 24-27.9)and obese(BMI ?28)women,respectively,had a 1.69-fold(95%CI:1.51-1.88)and a 1.49-fold(95%Cl:1.31-1.69)risks of delivering a neonatal macrosomia.When compared with the control group,there was significant male dominance in the study group,the OR value was 0.62(95%CI:0.57-0.68).4.The multiple logistic regression analysis showed that maternal residence was independent factor of low birth weight.The risk of delivering a neonatal macrosomia was significantly higher in mothers residing in urban areas than in those living in ural areas,the OR value was 0.69(95%CI:0.48-0.98).Compared with the normal birth weight group,macrosomia had a 1.52-fold(95%CI:1.24-1.86,P=0.001)and a 1.50-fold(95%CI:1.19-1.92,P<0.001)risks of developing overweight and obesity iat the age of 7 years old.Conclusions1.There was significantly regional difference in the incidence of abnormal birth weight in Jiangsu province.Subei got first rank of the incidence of macrosomia,Suzhong followed and Sunan got last rank.Sunan got first rank of low birth weight,Suzhong followed and Subei got last rank.2.Gestational age,and maternal early pregnancy BMI?24 had positive effects on delivering a neonatal macrosomia.In contrast,female gender had a negative effect.3.The risk of delivering a neonatal macrosomia was significantly higher in mothers residing in urban areas than in those living in rural areas.4.Macrosomia increased predisposition to develop overweight and obesity on the beginning of their childhood.