母亲孕前体质指数和孕期体重增加及其交互作用对新生儿出生体重的影响

目的 研究孕妇孕前BMI和孕期增重对新生儿出生体重的影响及其交互作用。方法 应用队列研究方法,选取2014年1月至2015年3月在安徽省安庆市立医院住院分娩的孕妇进行问卷调查,收集孕妇基本情况,并通过医院电子病历信息系统获取孕妇及新生儿信息。采用χ²检验、多分类logistic回归、相乘模型和相加模型分析孕妇孕前BMI、孕期增重及其交互作用与新生儿出生体重的关系。结果 共纳入单胎活产孕妇2 881例,其中小于胎龄儿359例（12.46%）,大于胎龄儿273例（9.48%）。多分类logistic回归分析显示,控制可能的混杂因素后,孕前体重过低（aRR=1.33,95%CI：1.02~1.73）与孕期增重不足（aRR=1.64,95%CI：1.23~2.19）可增加小于胎龄儿发生风险,孕前超重/肥胖（aRR=1.86,95%CI：1.33~2.60）与孕期增重过多（aRR=2.03,95%CI：1.49~2.78）可增加大于胎龄儿发生风险;交互作用分析显示,未发现二者对新生儿出生体重存在交互作用。结论 母亲孕前体重和孕期增重与新生儿出生体重相关,但未发现二者之间的交互作用。

Association and interaction of pre-pregnant body mass index and gestational weight gain of women on neonatal birthweight

Objective To investigate the association between maternal pre-pregnant body mass index and gestational weight gain, as well as their interaction on neonatal birthweight.Methods We built a cohort in Anqing Municipal Hospital from January 2014 to March 2015, enrolling pregnant women who decided to give birth in this hospital. All women were asked to fill a questionnaire for basic information collection. Medical information of both pregnant women and their newborns were obtained through electronic medical record. Chi-square analysis, multinomial logistic regression, multiplicative and additive interaction methods were used to analyze the association between pre-pregnant body mass index and gestational weight gain as well as their interactions on birth weight of the neonates.Results A total of 2 881 pregnant women were included in this study. Of the 2 881 newborns, 359 (12.46%) were small for gestational age (SGA) and 273 (9.48%) were large for gestational age (LGA). After adjusting the possible confounding factors, results from the multinomial logistic regression showed that pre-pregnancy underweight women were more possible to deliver SGA (aRR=1.33, 95% CI:1.02-1.73). If the gestational weight gain was below the recommended criteria, the risk of SGA (aRR=1.64, 95% CI:1.23-2.19) might increase. Pre-pregnancy overweight/obese could increase the risk of being LGA (aRR=1.86, 95% CI:1.33-2.60). Maternal gestational weight gain above the recommendation level was associated with higher rates of LGA (aRR=2.03, 95% CI:1.49-2.78).Results from the interaction analysis showed that there appeared no significant interaction between pre-pregnancy BMI and gestational weight on birthweight.Conclusion Pre-pregnancy body mass index and gestational weight gain were independently associated with neonatal birthweight while pre-pregnancy BMI and gestational weight gain did not present interaction on birthweight.