摘要目的 探讨孕妇孕前BMI、孕期增重对新生儿出生体重的影响.方法 以来自西南3省的5 395名孕妇为研究对象,根据WHO推荐的BMI分类标准将孕妇分为孕前低体重组、正常体重组、超重组以及肥胖组.按照美国医学研究院推荐的孕期增重标准定义各组孕妇孕期增重是否适宜.采用无序多分类logistic回归模型分析孕前BMI和孕期增重与新生儿出生体重的关系.结果 调整相关混杂因素后,孕前BMI较低(OR=1.91,95％CI:1.47～2.50)是分娩小于胎龄儿(SGA)的危险因素,但可降低分娩大于胎龄儿(LGA)的风险(OR=0.55,95％CI:0.47～0.66).孕期增重不足会使SGA的发生风险增加(OR=1.57,95％CI:1.21～ 2.03),分娩LGA的风险降低(OR=0.48,95％CI:0.41～ 0.57).孕前超重肥胖(OR=1.85,95％CI:1.58～ 2.17)以及孕期增重过多(OR=1.87,95％CI:1.67 ～ 2.11)与LGA的发生风险呈正相关.分层分析显示孕期增重不足仅会使孕前BMI较低和正常的孕妇分娩SGA的风险升高,对孕前超重肥胖的孕妇分娩SGA的风险没有影响.结论 孕前BMI和孕期增重是新生儿出生体重的重要影响因素,应加强孕妇健康教育、合理控制孕期增重.

abstractsObjective To explore the effects of both pre-gestational BMI and gestational weight gain (GWG) on the birth weight of neonates.Methods A total of 5 395 pregnant women were selected from the Southwest areas of China (Sichuan/Yunnan/Guizhou) and were divided into groups as pre-gestational underweight,normal weight,overweight and obesity,according to the WHO Recommendation on BMI Classification.Guidelines on Pregnancy weight were adopted from the Institute of Medicine to confirm the accuracy of GWG.Multinomial logistic regression model was used to assess the associations between pregestational BMI and GWG,on the birth weight of the neonates.Results After adjusting for related confounders,low pre-gestational BMI appeared as a risk factor for SGA (OR=1.91,95％CI:1.47-2.50),and was also associated with the decreased risk of LGA (OR=0.55,95％CI:0.47-0.66).Inadequate GWG was both associated with the increased risk of delivering SGA (OR=1.57,95％CI:1.21-2.03) and the decreased risk of LGA (OR=0.48,95％CI:0.41-0.57).Pre-gestational overweight/obesity (OR=1.85,95％CI:1.58-2.17) and excessive GWG (OR=1.87,95％CI:1.67-2.11) were both positively associated with the risks on LGA.Data from the stratified analysis indicated that inadequate GWG was positively associated with the risk of SGA among underweight or normal weight women (all P＜0.05),but not with those overweight/obese women.Conclusions Pre-gestational BMI and GWG were important influencing factors on the birth weight of neonates.Health education programs for pregnant women should be intensified and gestational weight gain should also be reasonably under control.