Association Of Gestational Weight Gain Rate With Offspring Early-childhood Growth And Obesity Risk

Objectives:Gestational weight gain is an important factor for maternal and offspring health,but evidence on associations of gestational weight gain rate（GWGR）in each trimester with offspring growth was limited.In this study,we aimed to（1）explore the associations of GWGR in different trimesters with birth outcomes and offspring growth from birth to 2 years old,and（2）to explore the associations of GWGR in different trimesters with offspring BMI trajectory from birth to 2 years old and risk of 2-year overweight/obesity.Methods:Based on a prospective cohort study,we enrolled 8703 mother-infant pairs during 2012 to 2014 in Wuhan.GWGR in each trimester was categorized as inadequate,adequate and excessive by 2009 US Institute of Medicine guidelines.Weight-for-age（ZWAZ）,height-for-age（ZHAZ）and BMI-for-age z-scores（ZBMI）were calculated based on age-and sex-specific World Health Organization（WHO）child growth standard.GWGR was applied in analyses as continuous and categorical variable.（1）In part 1,Logistic regression was used to estimate the associations of GWGR in different trimesters with small for gestational age（SGA）,large for gestational age（LGA）,low birth weight（LBW）and macrosomia.Linear mixed model was used to estimate the associations of GWGR in different trimesters with average ZWAZ,ZHAZ and ZBMI across birth to 2 years old,and generalized linear model was used to estimate the associations of GWGR in different trimesters with birth size and age-specific anthropometry.（2）In part 2,among the 8703 mother-infant pairs enrolled during 2012 to 2014,we only included 5071 children who had BMI data at birth,1month,6 months,1 year old and 2 years old.We retrieved children’s anthropometry data measured at 3 months,8 months and 18 months in community health examination from children’s health database.Overweight/obesity at 2 years old was defined as ZBMI more than 85^th percentile of WHO child growth chart.Group-based trajectory model was used to identify the BMI trajectory from birth to 2 years old.Multinomial logistic regression was applied to explore the associations of GWGR in different trimesters with children BMI trajectory.Logistic regression was applied to explore the associations of GWGR in different trimesters with overweight/obesity risk at 2 years old.Results:（1）Excessive GWGR in the 1^st trimester was associated with an increased OR of 1.49（95%CI:1.14,1.96）for macrosomia.Inadequate GWGR in the 2^nd trimester was associated with an increased OR of 1.28（95%CI:1.05,1.55）for SGA,and excessive GWGR in the 2^nd trimester was associated with an increased OR of 1.62（95%CI:1.38,1.89）,and1.95（95%CI:1.07,2.88）for LGA and macrosomia,respectively.Inadequate GWGR in the3^rd trimester was associated with an increased OR of 1.76（95%CI:1.07,2.88）for LBW.（2）Results of linear mixed model showed that GWGR in each trimester was positively associated with ZWAZ,ZHAZ and ZBMI across birth to 2 years old.Greater GWGR in the1^st trimester（per 0.2 kg/w）was associated with increased ZWAZ（β=0.03,95%CI:0.01,0.04）,ZHAZ（β=0.02,95%CI:0.001,0.03）and ZBMI（β=0.03,95%CI:0.01,0.04）.Greater GWGR in the 2^nd trimester（per 0.2 kg/w）was associated with increased ZWAZ（β=0.12,95%CI:0.10,0.14）,ZHAZ（β=0.08,95%CI:0.06,0.09）and ZBMI（β=0.12,95%CI:0.11,0.14）.Greater GWGR in the 3^rd trimester（per 0.2 kg/w）was associated with increased ZWAZ（β=0.06,95%CI:0.04,0.07）,ZHAZ（β=0.04,95%CI:0.02,0.05）and ZBMI（β=0.06,95%CI:0.04,0.07）.（3）Results of generalized model showed that greater GWGR in each trimester was positively associated with birth weight,birth length and Ponderal Index.Greater GWGR in the 1^st and 2^nd trimester was positively associated with 1-month,6-month,1-year and 2-year ZWAZ,while greater GWGR in the 3^rd trimester was positively associated with 1-month,1-year and 2-year ZWAZ.Similar results were observed in associations of GWGR with offspring age-specific ZHAZ and ZBMI.（4）We identified 5 BMI trajectories from birth to 2 years old:“lower BMI gain”（8.44%）,“catch-up growth”（12.36%）,“stable median BMI”（41.02%）,“higher BMI gain”（33.29%）and“increasing BMI gain”（4.89%）.A total of 885（17.45%）children were overweight/obesity at 2 years old.（5）Inadequate GWGR in the 1^st trimester was associated with an increased OR of 1.19（95%CI:1.001,1.42）for lower BMI gain,and excessive GWGR in the 1^st trimester was associated with an increased OR of 1.10（95%CI:1.01,1.21）for higher BMI gain.Inadequate GWGR in the 2^nd trimester was associated with an increased OR of 1.29（95%CI:1.11,1.50）for catch-up growth.GWGR in the 3^rd trimester（per 0.2 kg/w change）was associated with an increased OR of 1.12（95%CI:1.003,1.25）,and 1.07（95%CI:1.01,1.14）for increasing BMI gain and 2-year old overweight/obesity risk,respectively.Conclusions:GWGR in different trimesters was positively associated with birth size and offspring growth from birth to 2 years old.Inadequate and excessive GWGR was related to increased risk of adverse birth outcomes,as well as affected offspring growth trajectory and overweight/obesity risks.The results indicated the importance of women controlling appropriate GWGR during pregnancy.