孕期增重与孕前BMI对子代体格发育的影响

Effects of gestational weight gain and pre-pregnancy BMI on infant physical growth

目的探讨孕期增重与孕前体质量指数(BMI)对子代身长、体质量及BMI的影响。方法 2010年2—10月在上海新华医院选取225名孕妇,行孕前检查,孕28~36周进行问卷测评,构建线性回归模型分析孕期增重的影响因素。根据孕前BMI分为孕前低体质量组(BMI<18.0 kg/m^2)、正常体质量组(18.0~24.9 kg/m^2)、超重与肥胖组(≥25.0 kg/m^2)。随访记录婴儿0、6、12、18、24月龄时的体质量(kg)、身长(cm)及BMI。采用多元线性回归分析孕前不同体质量和孕期增重对不同年龄段婴儿的身长、体质量的影响。并采用重复测量的Mixed模型分析孕前不同体质量和孕期体质量增重对2岁以内婴儿的身长、体质量增长趋势的影响。结果 (1)母亲学历、孕前BMI与孕期增重呈负相关。(2)在婴儿0~2岁的各阶段,孕期增重与孕前BMI都与子代体质量、身长及BMI呈线性正相关。根据婴儿性别分组比较,孕期增重对男婴影响更大,孕前BMI对女婴影响更大(P<0.05)。(3)重复测量分析孕期增重对子代各年龄阶段标准化体质量、身长、BMI增长趋势的影响,发现不同孕期增重水平的子代体质量、身长、BMI存在差异,但没有显著改变子代的体质量、身长增长趋势及BMI增长趋势。结论孕前BMI可以对孕期增重情况产生影响,孕期增重和孕前BMI分别对子代体格发育产生影响。孕期增重、孕前BMI对子代生长发育影响存在性别差异。

Objective To explore the effects of gestational weight gain（GWG） and pre-pregnancy body mass index（BMI） on infant height,weight and BMI before the age of 2 years.Methods A total of 225 pregnant women were recruited at prenatal care clinics in Shanghai Xinhua Hospital from February to October 2010.Maternal pre-pregnancy weight and height were self-reported,and a series of questionnaires were completed from the 28 th to 36 th gestational week.Multiple linear regression was modeled to explore the influencing factors of GWG.According to pre-pregnancy BMI,the women were divided in low weight group（BMI18.0 kg/m^2）,normal weight group（18.0～24.9 kg/m^2）,and overweight group（≥25.0 kg/m^2）.Infant weight,length and BMI were followed up at birth,6,12,18,and 24 months old.The relationship between pre-pregnancy BMI,GWG and the infant standardized weight,length and BMI was analyzed.Mixed model with repeated measures at each followed age was then established to assess infant weight,height and BMI growth trends.Results（1） Mother＇s pre-pregnancy BMI and education level were negatively related with GWG.（2） GWG and prepregnancy BMI were positively correlated with infant weight,length and BMI at each follow-up stage before the age of 2years.GWG had a greater impact on the boys＇ weight and length than on the girls＇（P〈0.05）,whereas pre-pregnancy BMI had greater impacts on the girls＇ weight and BMI growth than on the boys＇（P〈0.05）.（3） Mixed model of repeated measures indicated that,independent of age,a higher GWG level was associated with a higher infant standardized weight,length and BMI.But there were no significant effects on trends of weight,length and BMI.Conclusion Pre-pregnancy BMI is negatively correlated with GWG.GWG and pre-pregnancy BMI are both positively associated with infant weight,length and BMI growth before the age of 2 years and the association has gender differences.