天津地区双胎孕妇妊娠期增重趋势探讨

目的 初探天津地区不同孕前BMI双胎孕妇妊娠期增重趋势和各妊娠期推荐增重范围。方法 回顾性分析2010年1月至2018年11月在天津市分娩且有完整产检的1 346例健康双胎孕妇数据，按照孕前BMI分为体重不足组（BMI<18.5,n=117）、标准体重组（18.5≤BMI≤23.9,n=783）、超重组（24.0≤BMI≤27.9,n=320）、肥胖组（BMI≥28.0,n=126）。绘制各组孕妇的妊娠期体重增长曲线，按P²5～P75计算不同组别双胎孕妇妊娠早、中、晚期适宜增重范围，分析孕前BMI与新生儿体重的关系。结果 孕前BMI与年龄呈正相关（r=0.06,P<0.05），与分娩孕周呈负相关（r=-0.12,P<0.001），双胎之间出生体重呈正相关（r=0.69,P<0.001）。四组孕妇妊娠期适宜增重范围分别是:体重不足组20.27（17.00～24.24）kg，标准体重组20.95（16.64～25.66）kg，超重组16.94（13.39～20.62）kg，肥胖组16.44（11.29～21.79）kg，差异有统计学意义（P<0.01）。孕前BMI与双胎新生儿出生体重之间差异无统计学意义（P>0.05）。结论 本研究初步得出我国北方城市天津不同孕前BMI双胎孕妇在妊娠早、中、晚期的适宜增重范围及增重速度，为现有指南中缺少的孕前体重不足组双胎孕妇的妊娠期增重范围提供参考。

Trend of weight gain during pregnancy of twin-pregnant women in Tianjin

Objective To explore the trend of weight gain and recommended range of weight gain of twin pregnant women with different levels of pre-pregnancy body mass index (BMI) in Tianjin. Methods Data of 1 346 healthy twin pregnant women who delivered in Tianjin from January 2010 to November 2018 with complete examination information were collected. They were divided into four groups: underweight (BMI<18.5, n=117), normal (18.5≤BMI≤23.9, n=783), overweight (24.0≤BMI≤27.9, n=320) and obese (BMI≥28.0, n=126) according to pre-pregnancy BMI. Four group curves of weight gain were plotted. Appropriate range of weight gain of twin pregnant women in different groups was calculated at each trimester according to P²5-P
75. The relationship between pre-pregnancy BMI and neonatal weight was analyzed. Results Pre-pregnancy BMI was positively correlated with age (r=0.06, P<0.05) and negatively correlated with gestational age (r=-0.12, P<0.001). Birth weight was positively correlated between twins (r=0.69, P<0.001). Appropriate range of weight gain during pregnancy was 20.27 (17.00-24.24)kg for underweight group, 20.95 (16.64-25.66) kg of normal group, 16.94 (13.39-20.62) kg for overweight group, and 16.44 (11.29-21.79) kg for obese group respectively. There were significant differences among the 4 groups (P<0.01). However, there was no significant correlation between the pre-pregnancy BMI and twins’ birth weight (P>0.05). Conclusion This study preliminarily concludes the suitable range of weight gain and rate of weight gain for twin-pregnant women with different pre-pregnancy BMI at the first, second and third trimester in Tianjin, northern China, and provides a reference for the range of weight gain during pregnancy in twin pregnant women with low pre-pregnancy weight, which the existing guidelines lacks.