摘要目的 分析足月单胎孕妇前后2次分娩的新生儿出生体重的特点,探讨再次分娩为巨大儿的影响因素. 方法 本研究为病例对照研究.回顾性收集2005年1月至2017年12月在北京大学第一医院前后分娩2次的1 920例单胎足月孕妇的临床资料.无论前次分娩是否为巨大儿,根据本次分娩是否为巨大几分为巨大儿组(n=122)和非巨大儿组(n=1 798).亚组:(1)前次分娩巨大儿的孕妇(n=117),根据本次分娩是否为巨大儿分为巨大儿组(n=27)和非巨大儿组(n=90);(2)前次分娩非巨大儿孕妇(n=1 803),根据本次分娩是否为巨大儿分为巨大儿组(n=95)和非巨大儿组(n=1 708).比较巨大儿组和非巨大儿组孕妇的分娩间隔以及本次妊娠的年龄、孕前体重指数、孕期增重、口服葡萄糖耐量试验时间-血糖曲线的曲线下面积、体重潴留、妊娠合并糖尿病(包括妊娠期糖尿病及糖尿病合并妊娠)和妊娠期高血压疾病发生率及剖宫产率.采用t检验、x2检验及logistic回归分析进行统计学分析. 结果 (1)1 920例单胎足月孕妇本次分娩的新生儿出生体重高于前次分娩[(3 443±378)与(3 403±396)g,t=-4.119,P＜0.001],但巨大儿比例差异无统计学意义[6.4％(122/1 920)与6.1％(117/1 920),x2=3.237,P=0.198].本次分娩巨大儿组孕妇的孕前体重指数、孕期增重和前次分娩巨大儿(巨大儿史)的比例均显著高于非巨大儿组[(23.6±3.4)与(22.7±3.1)kg/m2,t=-2.882,P=0.004;(13.4±5.0)与(12.4±4.1) kg,t=-2.522,P=0.037;22.1％ (27/122)与5.0％(90/1 798),x2=58.554,P＜0.001];纳入以上3项单因素分析差异有统计学意义的因素进行多因素logistic回归分析发现,巨大儿史(OR=4.979,95％CI:3.052～8.122,P＜0.001)、孕前体重指数(OR=1.084,95％CI:1.023～1.149,P=0.001)和孕期增重(OR=1.077,95％CI:1.031～1.125,P=0.007)是本次分娩巨大儿的危险因素.(2)亚组分析:2次分娩均为巨大儿的孕妇的孕前体重指数高于前次分娩巨大儿但本次分娩非巨大儿者[(25.8±4.3)与(23.9±2.9)kg/m2,t=2.600,P=0.011];前次分娩非巨大儿本次分娩巨大儿的孕妇的孕期增重显著高于2次分娩均为非巨大儿者[(13.5±4.2)与(12.5±4.1) kg,t=-2.404,P=0.016]. 结论 同一孕妇前后2次单胎足月妊娠,再次分娩的新生儿出生体重稍高于前次,但巨大儿的发生率相近.孕前体重指数、孕期增重和巨大儿史是再次分娩巨大儿的独立危险因素.针对有巨大儿史的孕妇,再次妊娠应更注重降低孕前体重指数;针对无巨大儿史的孕妇,再次妊娠需注重孕期体重管理.

abstractsObjective To explore the characteristics of neonatal birth weight (BW) in two consecutive term singleton pregnant women and to investigate the influencing factors of macrosomia in the second birth.Methods In this case-control study,medical records of 1 920 singleton full-term pregnant women who gave birth twice in Peking University First Hospital from January 2005 to December 2017 were reviewed.All subjects were divided into two groups according to neonatal BW at the second birth regardless of the first one:macrosomia group (n=122) and non-macrosomia group (n=l 798).Then,those two groups were further divided into four sub-groups based on the neonatal BW in the first birth:macrosomia at both deliveries (n=27),macrosomia at the second time and non-macrosomia at the first time (n=95),non-macrosomia at the second time and macrosomia at the first time (n=90) and non-macrosomia at both deliveries (n=l 708).The differences of delivery interval,and the maternal age,pre-pregnancy body mass index (BMI),weight gain during pregnancy,area under the curve of oral glucose tolerance test results,weight retention,the incidence of diabetes in pregnancy (including gestational diabetes mellitus and diabetes mellitus complicated with pregnancy),incidence of hypertensive disorders during pregnancy and cesarean section rate at the second pregnancy between the groups and sub-groups were compared with t-test,Chi-square test and logistic regression analysis.Results (1) The total average neonatal BW in the second pregnancy was higher than that in the first [(3 443 ± 378) vs (3 403 ± 396) g,t=-4.119,P＜0.001].However,the proportion of macrosomia in each group was similar [6.4％ (122/ 1 920) vs 6.1％ (117/1 920),x2=3.237,P=0.198].The pre-pregnancy BMI,weight gain during pregnancy and proportion of previous macrosomia in the macrosomia group were significantly higher than those in non-macrosomia group [(23.6±3.4) vs (22.7±3.1) kg/m2,t=-2.882,P=0.004;(13.4±5.0) vs (12.4± 4.1) kg,t=-2.522,P=0.037;22.1％ (27/122) vs 5.0％ (90/1 798),x2=58.554,P＜0.001].Logistic regression analysis showed that previous macrosomia (OR=4.979,95％CI:3.052-8.122,P＜0.001),pre-pregnancy BMI (OR=1.084,95％CI:1.023-1.149,P=0.001) and weight gain during pregnancy (OR=1.077,95％CI:1.031-1.125,P=0.007) were influencing factors for macrosomia in the index delivery.(2) The pre-pregnancy BMI in the subgroup of macrosomia at both deliveries was significantly higher comparing to the subgroup of non-macrosomia at the second time and macrosomia at the first time [(25.8±4.3) vs (23.9±2.9) kg/m2,t=-2.600,P=0.011].Women in the subgroup of macrosomia at the second time and non-macrosomia at the first time had higher weight gain during second pregnancy than the subgroup of non-macrosomia at both deliveries [(13.5 ± 4.2) vs (12.5 ±4.1) kg,t=-2.404,P=0.016].Conclusions For two consecutive term singleton pregnancies,the average neonatal BW in the second time is slightly higher than that in the first,but the incidence of macrosomia is similar.Pre-pregnancy BMI,weight gain during pregnancy and macrosomia in the first birth are influencing factors for macrosomia in the second pregnancy.More attention should be paid to pre-pregnancy BMI reduction in women with history of macrosomia.For women without a history of macrosomia,weight management should be emphasized during the second pregnancy.