城市女性孕期体重增重的影响因素分析

目的 了解城市女性在孕中晚期体重增重趋势及其相关因素,为孕妇合理控制体重提供科学依据。方法 采用历史性队列研究的方法,调查于2015年在北京市某三甲医院建档产检并生产的孕妇1 176例,采用病案查询法获取孕妇的一般情况,以及建档时(孕6~8周)、孕16、20、24、28、32、36周及分娩当天体重数据。通过分析孕妇体重增幅及增重速度,以了解妊娠期体重增重的趋势及其相关影响因素。结果 本次调查提示调查对象孕期总增重(13.8±4.3)kg,增重速度(周增重)从孕24周后递减,孕中期高于孕晚期。孕期增重与基础体质指数(BMI)密切相关,基础超重/肥胖组孕期总增重(11.8±4.6)kg]及增速(周增重)明显低于低体重组(14.1±3.3)kg]和正常组(13.9±3.9)kg],差异有统计学意义(P<0.05),其中超重/肥胖组增速整体较平缓。参考美国医学研究所(IOM,2009)标准,41.2%调查对象孕期增重适宜,23.3%增重不足,34.5%增重过多;基础低体重组孕期易增重不足比例较高(31.7%),而超重/肥胖孕妇易增重过多(58.6%)。分娩年龄≥35岁组的孕妇体重增幅低于年龄＜35岁组,但变化趋势差异无统计学意义(P＞0.05),不同年龄组孕妇各孕周体重增速均呈递减趋势,差异有统计学意义(P＜0.001),其中年龄≥35岁组增速变化平缓(P＞0.05)。经产妇体重增幅低于初产妇(P＜0.05),但两组体重增速差异无统计学意义(P＞0.05)。多因素分析显示孕期增重与怀孕年龄、基础BMI、分娩孕周有关,方程为Y=9.027-0.114X₁-0.258X₂+0.352X₄。结论 孕妇孕中期增重高于孕晚期,孕期总增重与基础体质指数密切相关。

Factors influencing weight gain during pregnancy among urban women

Objective To investigate the weight gain in the second and third trimesters of pregnancy and its related factors among urban women so as to provide a scientific basis for rational control of body weight in pregnant women. Methods Historical cohort study was used to survey 1,176 pregnant women who had antenatal examination records and underwent prenatal check-up and delivery in a third-grade class-A hospital in Beijing in 2015. Medical record inquiry method was employed to investigate the data about the pregnant women’s general information and their body weight at the 6th-8th, 16th, 20th, 24th, 28th, 32nd and 36th weeks of gestation and on parturition day. We explored the trend of weight gain during pregnancy and its related influencing factors through analyzing the pregnant women’s gestational weight gain and weekly weight gain. Results The total gestational weight gain of the surveyed pregnant women was (13.8±4.3) kg averagely. The weekly weight gain decreased from the 24th week of pregnancy, and it was found to be higher in the second trimester than in the third one. The gestational weight gain was closely correlated with body mass index (BMI) at the 6th-8th weeks of pregnancy. The total gestational weight gain ((11.8± 4.6) kg) and weekly weight gain in the overweight/obesity group were significantly lower than those in the low body weight group ((14.1±3.3) kg) and the normal body weight group ((13.9±3.9) kg), showing statistically significant differences (both P<0.05), but the changes in the weekly weight gain in the overweight/obesity group were generally stable. According to the 2009 Institute of Medicine Guidelines, 41.2% of the pregnant women had proper weight gain, 23.3% insufficient weight gain and 34.5% excessive weight gain. The proportion of insufficient gestational weight gain was higher in the low body weight group (31.7%), but the proportion of excessive gestational weight gain was higher in the overweight/obesity group (58.6%). The gestational weight gain was lower in pregnant women aged ≥35 years than in ones aged < 35 years, but no statistically significant difference was found in the changing trend (P>0.05). The weekly weight gain of different age groups showed a decreasing tendency and statistically significant differences (P<0.001), of which the changes in the weekly weight gain of the age group of ≥35 years were stable (P>0.05). The gestational weight gain was lower in multiparas than in primiparas (P<0.05), without a statistically significant difference (P>0.05). Multivariate analysis showed that weight gain during pregnancy was correlated with maternal age, BMI at the 6th-8th weeks of pregnancy and pregnancy week at delivery, and the equation was Y=9.027-0.114X₁-0.258X₂+0.352X₄. Conclusion The weight gain during pregnancy of the pregnant women is found to be higher in the second trimester in comparison with the third one, and the total gestational weight gain is closely associated with BMI at the 6th-8th weeks of pregnancy.