Analysis Of Nutritional Components And Influence Factors Of Breast Milk Based On A Birth Cohort

Objectives1.to analyze the nutritional components of breast milk at the different stages of lactation in Wuhan,and to explore its changes rule.2.to access the influential factors that affect the breast milk nutrition,and to provide a scientific basis for guiding breast feeding.MethodThe study was based on Health Birth Cohort Study(HBC study),A total of 571 lactating mothers were selected for the analysis of breast milk composition in Wuhan Women and Children's Health Care Center during August 2014 to October 2016.A questionnaire,maternal health care consultation,was invited to complete to collect the baseline data of the lactating mothers in pre-pregnancy,pregnancy,intrapartum and the newborns.Baseline data include age,occupation,pre-pregnancy BMI,weight gain during pregnancy,and neonatal gender,birth weight and so on.Investigators use the national standard breast milk analyzer to detect breast milk components,which is protein,fat,lactose and non-milk fat solid;detection time include one month and six month postpartum.Paired t test was used to describe the dynamic changes of breast milk nutrition in different lactation stages;Independent samples t test,one-way ANOVA,and multivariable linear regression model were used to explore the affecting factors of breast milk.Results1.Variation of Nutritional Components in Breast Milk(1)Protein content:1 month,6 months postpartum of breast milk protein content are 2.99 ± 0.37 g / 100 ml,2.33 ± 0.91 g / 100 ml respectively;The t value of the milk protein content of the different lactating stages are 15.67,P <0.001,it indicates that the protein content is the highest in 1 month postpartum,and decreases with prolonged lactation.(2)Fat content : 1 month,6 months postpartum of breast milk fat content are4.17±1.68g/100 ml,4.20±1.97g/100 ml respectively;The t value of the milk fat content of the different lactating stages are-0.267,P=0.789,it indicates that the fat content is little change,and maintains a constant in the lactation.(3)Lactose content:1 month,6 months postpartum of breast milk lactose content are 4.45±0.34g/100 ml,5.08±1.41g/100 ml respectively;The t value of the milk lactose content of the different lactating stages are-10.98,P<0.001,it indicates that the lactose content is the highest in 6 month postpartum,and increases with prolonged lactation.(4)Solids-not-fat content:1 month,6 months postpartum of breast milk solids-notfat content are8.06±0.50 g/100 ml,8.94±2.35 g/100 ml respectively;The t value of the milk lactose content of the different lactating stages are-9.01,P<0.001,it indicates that the solids-not-fat content is the highest in 6 month postpartum,and increases with prolonged lactation.2.Analysis of Influencing Factors of Nutritional Components in Breast Milk(1)Protein content:In 1 month postpartum,midday rest during late pregnancy for protein content is the main influential factors and explained 1.7% of the variance;In 6 months postpartum,season,women add folic acid supplementation after 3 months of pregnancy are the main influential factors and explained 33.7% of the variance.(2)Fat content:In 1 month postpartum,pregnancy BMI,weight gain during pregnancy,women add folic acid supplementation after 3 months of pregnancy and season are the main influential factors and explained 5.9% of the variance;In 6 months postpartum,women add folic acid supplementation after 3 months of pregnancy is the main influential factors and explained 1.7% of the variance.(3)Lactose content:In 1 month postpartum,season is the main influential factors and explained 1.3% of the variation;In 6 months postpartum,season,women add folic acid supplementation after 3 months of pregnancy and fetal growth restriction are the main influential factors and explained 33.4% of the variance.(4)Solids-not-fat content:In 1 month postpartum,season and pregnancy discomfort are the main influential factors and explained 2.4% of the variance;In 6 months postpartum,season,women add folic acid supplementation after 3 months of pregnancy and fetal growth restriction are the main influential factors and explained 28.1% of the variance.Conclusions1.The content of protein in breast milk decreases with the prolongation of the lactation stage,while the lactose and solids-not-fat increase with the prolongation of the lactation stage;the fat is basically maintained at a constant level,and the change is benefit to the healthy growth of the baby.2.Season,women add folic acid supplementation after 3 months of pregnancy,prepregnancy BMI,weight gain during pregnancy,pregnancy discomfort and fetal growth restriction are the main influencing factors of breast milk nutrition.In the intervenable factors,In addition to women add folic acid supplementation after 3 months of pregnancy,midday rest during late pregnancy is also the factor of breast milk nutrition,However,this factor has a low degree of explanation for the nutritional content of breast milk.Therefore,further study is necessary to explore the influential factors of breast milk nutrition more deeply.