基于孕前体重指数指导孕期增重对于控制新生儿过重的意义

Research of relationship of pregnancy weight gain based on pre-pregnancy body mass index and large for gestational age (LGA) fetus

目的调查孕前体重指数指导孕期增重范围对控制新生儿体重过大的临床意义。方法属回顾性研究。选取2010年1月-2015年6月产检并住院分娩孕产妇病例资料,参照国内文献推算的增重范围,分析不同孕前体重指数水平下,产妇孕期增重与分娩大于胎龄儿之间的关系。结果共有16 257例对象纳入,其中分娩大于胎龄儿者1 924例(11.8%)。对数线性模型提示孕前体重指数高、孕期增重值大(χ2=15.35,P=0.043),5个层次以及增重超过推荐范围(χ2=10.10,P=0.0015),4个层次者更易分娩大于胎龄儿。Logistic回归表明各孕前体质指数水平下,分娩大于胎龄儿风险值(a OR∧,与对应参照水平比较)随孕期增重加剧而升高,其中孕前体重指数偏瘦者若增重≥19.5 kg,大于胎龄儿风险(a OR∧=6.5,95%CI=2.9,9.7)远超过相同增重情况下孕前体重指数超重的对象(a OR∧=2.8,95%CI=1.9,5.7);且在孕期"增重超过推荐范围"的对象中,孕前体重指数偏瘦者分娩大于胎龄儿风险最高(a OR∧=4.1,95%CI=2.9,5.3)、孕前体重指数超重者风险最低(a OR∧=2.4,95%CI=1.0,4.1)。结论孕前体重指数未超重的孕妇也需严格控制孕期增重。国内需尽快建立基于孕前体重指数制定的孕期增重指南。

Objective To analyze whether pre-pregnancy body mass index （BMI） modifies the risk of large for gestational age （LGA） fetus within variant pregnancy weigh gains. Methods Retrospectively analyzed clinical data of women hospitalized from Jan 2010 to June 2015. A Chinese literature was referred for recommended pregnancy weigh gain based on pre-pregnancy BMI （recommended weigh gain ranges）. The risk of LGA was calculated. Results Data of 16,257 women were analyzed, and among them 11.8% （n = 1,924） were LGA. Interaction-terms analysis of LGA risk factors indicated relationships amid pre-pregnancy BMI and pregnancy weight gain （χ^2= 15.35, P = 0.043, 5-level variable） as well as pre-pregnancy BMI and recommended weight gain ranges （χ^2 = 10.10, P = 0.002, 4- level variable）. Binary Logistic regression showed increasing aORs of LGA with pregnancy weight gain ongoing in different pre-pregnancy BMI levels. For women categorized as lean for pre-pregnancy BMI, pregnancy weight gain ≥19.5 kg contributed six folds risks of LGA （aO^R,= 6.5, 95%CI = 2.9, 9.7）, much higher than women obese for pre-pregnaney BMI （aO^R = 2.8, 95%CI = 1.9, 5.7）. For women exceeding recommended weight gain ranges, those lean for pre-pregnancy BMI suffered highest risk of LGA （aO^R= 4.1, 95%CI = 2.9, 5.3）, while women obese for pre-pregnancy BMI were lowest in such a risk （aO^R= 2.4, 95%CI = 1.0, 4.1）. Conclusions Pregnancy weigh gain should be emphasized more for women who are lean for pre-pregnancy BMI. Pregnancy weight gain recommendations for Chinese population based on pre-pregnancy BMI should be established.