孕期不同阶段增重与新生儿出生体重的相关性

目的:探讨正常足月孕妇孕期不同阶段增重与新生儿出生体重的关系。方法:回顾分析2014年1月至2014年12月在嵊州人民医院定期产前检查并且正常足月单胎孕妇2634例的临床资料。根据孕前体重指数(BMI)分为3组:低体重组(18.5kg/m2),正常体重组(18.5~23.9kg/m2),超重组(24~27.9kg/m2)。收集孕妇早、中、晚孕期的体重增加值,分析孕期不同阶段增重与新生儿出生体重的关系。结果:低体重组、正常体重组和超重组孕期增重分别为15.0kg(12.7,17.7kg)、14.5kg(12.0,17.5kg)和13.0kg(9.0,16.0kg);新生儿出生体重分别为3230g(3000,3470g)、3330g(3090,3600g)和3437g(3140,3722g),3组比较差异均有统计学意义(P0.05)。低体重组、正常体重组和超重组早孕期增重分别为1.4kg(0.6,2.3kg)、1.1kg(0.6,2.1kg)和1.1kg(0.4,1.9kg);中孕期增重分别为7.8kg(6.5,9.4)kg、7.5kg(6.0,9.0kg)和6.5kg(4.8,8.1kg);晚孕期增重分别为5.8kg(4.2,7.5kg)、5.7kg(4.2,7.4kg)和5.1kg(3.5,7.0kg);同孕期3组比较,差异均有统计学意义(P0.05)。回归结果表明,除低体重组晚孕期和超重组早孕期以外,其余各孕期体重增加对新生儿出生体重均有促进作用。其中低体重组早孕期增重对新生儿体重增加影响最大(标准化回归系数0.21,P0.05);正常体重组和超重组中孕期增重对新生儿体重增加影响最大(标准化回归系数分别为0.18,0.10,P均0.05)。含哑变量的回归结果示,对整个研究群体而言,中孕期增重对出生体重的影响最大(标准化回归系数0.18,P0.05);相对于正常体重组早孕期增重对新生儿出生体重增加的影响而言,低体重组孕早期增重影响更大(标准化回归系数差为0.05,P0.05),而超重组最小(标准化回归系数差为-0.06,P0.05)。结论:孕前BMI和孕期不同阶段增重与新生儿出生体重有关;低体重组早孕期增重对新生儿出生体重增加影响最明显,而正常体重组和超重组则中孕期增重对新生儿体重增加最明显。因此,根据孕前BMI制定孕期不同阶段合理增重对于控制新生儿体重具有指导意义。

The relationship between weight gain in different trimesters of gestation and neonatal birth weight

Objective:To investigate the relationship between weight gain in different trimesters of gestation and the birth weight of neonates in normal full-term pregnant women.Methods:Retrospective analysis was made on 2634 cases of normal single-term pregnancies from Jan.2014 to Dec.2014 in Shengzhou People's Hospital.According to the pre-pregnancy body mass index (BMI),the pregnancies were divided into three groups:underweight (<18.5kg/m2),normalweight (18.5~23.9kg/m2)and overweight(24~27.9kg/m2),and weight gain was collected and recorded for all subjects in the first,second and third trimester respectively.The clinical data of the first trimester (<12 weeks),the second trimester (12 weeks to 27 weeks) and third trimester (≥28 weeks) of the three groups were collected and recorded.The relationship was analyzed between weight gain different trimesters of gestation and neonatal birth weight(NBW).Results:Underweight group,normalweight group and overweight group weight gain was 15.0(12.7,17.7)kg,14.5(12.0,17.5)kg and 13.0(9.0,16.0)kg respectively;and birth weight was 3230(3000,3470)g,3330(3090,3600)g and 3437(3140,3722)g respectively,and the three groups have significant difference with each other (P<0.05).Underweight group,normalweight group and overweight group weight gain was 1.4(0.6,2.3)kg,1.1(0.6,2.1)kg and 1.1(0.4,1.9)kg in the first trimester respectively;7.8(6.5,9.4)kg,7.5(6.0,9.0)kg and 6.5(4.8,8.1)kg in the second trimester respectively;and 5.8(4.2,7.5)kg,5.7(4.2,7.4)kg and 5.1(3.5,7.0)kg in the third trimester respectively;there were no significant differences between the three groups (P<0.05).The results of regression analysis showed that except for underweight women in the third trimester and overweight women in the first trimester,the weight gain in each trimester was significantly positively correlated with NBW.The effect of underweight women was the strongest in the first trimester (Standardized regression coefficient 0.21,P<0.05);while normalweight and overweight women was the strongest in the second trimester(Standardized regression coefficient 0.18,0.10,P<0.05).Multivariate linear regression analysis showed that weight gain in the second trimester has the strongest effect on NBW with weight gain among the three trimesters in the whole population (standardized regression coefficient 0.18,P<0.05).In addition,compared with the normalweight group of the effect of weight gain in the first trimester,underweight group was the strongest(Standardized regression coefficient difference was 0.05,P<0.05),while overweight group was the lowest (standardized regression coefficient difference was-0.06,P<0.05).Conclusions:Pregnancy BMI and weight gain in different trimesters of gestation are related to neonatal birth weight.The effect of underweight women was the strongest in the first trimester,while normalweight and overweight women was the strongest in the second trimester.Therefore,according to pre-pregnancy BMI in different trimesters of pregnancy,it is a guiding significance to develop a reasonable weight gain for the control of NBW.