孕前体质指数及孕期增重对新生儿出生体重影响的前瞻性队列研究

  目的   分析孕妇孕前体质指数(body mass index, BMI)及孕期增重(gestational weight gain, GWG)与新生儿出生体重的关联性, 并探究孕妇孕前及孕中体重动态变化对新生儿低出生体重(low birth weight, LBW)及巨大儿的影响。   方法   收集中国孕产妇队列·协和纳入的孕早期孕妇孕前体重, 并随访至分娩后, 收集分娩前体重及新生儿出生结局。将孕妇孕前BMI分为低体重组、正常体重组及超重/肥胖组, 将GWG分为适宜、不足及过多组。采用多因素多分类(多项)Logistic回归分析模型探讨孕前BMI及GWG与新生儿出生体重的关系。   结果   孕前BMI及GWG与子代出生体重相关(均有P < 0.05)。孕前超重/肥胖(OR=2.339, 95% CI:1.674~2.282, P < 0.001)、GWG过多(OR=1.398, 95% CI:1.188~1.978, P=0.048)显示为巨大儿的危险因素, GWG不足(OR=1.479, 95% CI:1.461~1.679, P=0.035)显示为LBW的危险因素, GWG过多会降低LBW的发生风险(OR=0.428, 95% CI:0.225~0.817, P=0.010)。低BMI-GWG不足(OR=1.335, 95% CI:1.048~2.319, P=0.048)是LBW的危险因素; 正常BMI-GWG过多(OR=1.088, 95% CI:1.016~1.675, P=0.038)和超重/肥胖-GWG过多(OR=1.498, 95% CI:1.244~2.017, P=0.046)是巨大儿的危险因素。   结论   孕前BMI及GWG是影响新生儿出生体重的重要因素, 提示女性应合理控制孕前及孕中体重变化。

Effect of pre-pregnancy body mass index and gestational weight gain on birth weight of infants: a prospective cohort study

Objective To analyze the relationship between pre-pregnancy body mass index(BMI), gestational weight gain(GWG) and the birth weight of infants, and explore the effect of weight change before and during pregnancy on low birth weight(LBW) and macrosomia. Methods Women were enrolled by the Chinese Pregnant Women Cohort Study during first trimester. Each respondent’s weight before and during pregnancy and the birth weight of infant were collected after fellow up. Pre-pregnancy BMI was divided into underweight, normal and overweight/obesity groups and GWG was divided into suitable, insufficient and excessive groups. Multivariate Logistic regression was adopted to explore the relationship between pre-pregnancy BMI, GWG and newborn’s birth weight. Results Women’s pre-pregnancy BMI and GWG were associated with neonatal birth weight(all P<0.05). Pre-pregnancy overweight or obesity(OR=2.339, 95% CI:1.674-2.282, P<0.001) and excessive GWG(OR=1.398, 95% CI:1.188-1.978, P=0.048) were shown as risk factors for macrosomia. Insufficient GWG increased LBW risk(OR=1.479, 95% CI:1.461-1.679, P=0.035) while excessive GWG declined LBW risk(OR=0.428, 95% CI:0.225-0.817, P=0.010). Under weight-insufficient GWG was risk factor of LBW(OR=1.335, 95% CI:1.048-2.319, P=0.048) while normal BMI-excessive GWG(OR=1.088, 95% CI:1.016-1.675, P=0.038) and overweight/obesity-excessive GWG(OR=1.498, 95% CI:1.244-2.017, P=0.046) were associated with higher risk of delivering macrosomia. Conclusions Pre-pregnancy BMI and GWG were associated with infant’s birth weight and women were suggested to maintain their weight in recommended range before and during pregnancy.