肥胖孕妇孕期增重及其与不良妊娠结局的关系

Maternal weight gain during pregnancy in obese women and its relationship with adverse pregnancy outcomes

目的探讨肥胖孕妇孕期增重情况及其对不良妊娠结局的影响。方法回顾性纳入2014年1月至2016年12月就诊于首都医科大学附属北京妇产医院产科的肥胖(孕前体重指数≥30 kg/m^(2))、单胎妊娠孕妇513例。根据孕期增重分为增重不足组(增重<5 kg,n=83)、增重适宜组(增重5~9 kg,n=154)和增重过多组(增重>9 kg,n=276)。采用χ^(2)检验、Fisher精确概率法、Kruskal-Wallis检验和Mann-Whitney U检验比较3组肥胖人群的孕期增重特点、妊娠结局、新生儿结局以及产程特点,采用多因素logistic回归分析孕期增重对与肥胖相关的主要妊娠期并发症的影响。结果(1)238例早孕期增重>2.0 kg的人群中75.6%(180/238)发展为增重过多,275例早孕期增重≤2.0 kg的孕妇中,只有34.9%(96/275)发展为增重过多。(2)产后体重指数滞留(产后6周体重指数-孕前体重指数)在增重过多组高于增重适宜组[0.8 kg/m2(0.0~2.2 kg/m2)与-0.7 kg/m2(-1.6~0.0 kg/m2)],增重适宜组高于增重不足组[-2.5 kg/m2(-3.2~-1.5 kg/m2)](P值均<0.05)。(3)初次剖宫产率在增重不足组为29.9%(20/67),在增重适宜组为32.6%(42/129),均低于增重过多组[43.3%(104/240)](χ^(2)值分别为3.955和4.047,P值均<0.05);3组间妊娠期高血压疾病、小于胎龄儿、大于胎龄儿等其他主要不良妊娠结局发生率差异无统计学意义(P值均>0.05)。早孕期增重和中孕期行口服葡萄糖耐量试验前增重与妊娠期糖尿病的发生无关(aOR=1.038,95%CI:0.986~1.094,P=0.157;aOR=1.055,95%CI:1.000~1.113,P=0.051)。GDM孕妇诊断后接受了严格的营养管理,中、晚孕期增重及孕期总增重[3.0 kg(1.3~4.0 kg)、4.0 kg(2.0~6.0 kg)和9.0 kg(5.0~12.0 kg)]均低于非GDM孕妇[分别为3.0 kg(2.0~5.0 kg)、6.0 kg(4.0~8.0 kg)和10.7 kg(7.5~15.0 kg),Z值分别为-2.938、-6.352和-4.104,P值均<0.01]。结论早孕期是控制肥胖人群孕期增重的关键时机,控制孕期增重在适宜范围能够降低产后6周的体重滞留,但对于降低妊娠期糖尿病、妊娠期高血压疾病、大于和小于胎龄儿的发生风险意义不大。

Objective To analyze the maternal gestational weight gain(GWG)in women with pre-pregnancy obesity and its relationships with adverse pregnancy outcomes.Methods This retrospective cohort study recruited 513 obese women(pre-pregnancy body mass index≥30 kg/m2)with singleton pregnancy in Beijing Obstetrics and Gynecology Hospital,Capital Medical University from January 2014 to December 2016.All participants were divided into three groups according to GWG:inadequate(GWG<5 kg,n=83),adequate(5 kg≤GWG≤9 kg,n=154),and excessive(GWG>9 kg,n=276)groups.Chi-square test,Fisher's exact test,Kruskal-Wallis test,and Mann-Whitney U test were used to compare the clinical data among the three groups,including GWG,pregnancy and neonatal outcomes,and labor process.Multivariate logistic regression was performed to analyze the association between maternal GWG and main pregnancy complications associated with obesity.Results(1)Among 238 participants who gained more than 2.0 kg in the first trimester,75.6%(180/238)were in the excessive group,while the rate was 34.9%(96/275)among the participants who gained less than 2.0 kg.(2)Postpartum body mass index retention(body mass index at six weeks postpartum minus pre-pregnancy body mass index)was the highest in the excessive group,followed by the adequate group and the inadequate group[0.8 kg/m^(2)(0.0-2.2 kg/m^(2))vs-0.7 kg/m^(2)(-1.6 to 0.0 kg/m^(2))vs-2.5 kg/m2(-3.2 to-1.5 kg/m2),all P<0.05].(3)The rates of primary cesarean section in the inadequate and adequate groups were 29.9%(20/67)and 32.6%(42/129),which were lower than that in the excessive group[43.3%(104/240),χ^(2)=3.955 and 4.047,both P<0.05].There were no statistically significant differences in the incidence of gestational hypertension,small/large for gestational age,or other major adverse pregnancy outcomes among the three groups(all P>0.05).The weight gain in the first trimester and before the oral glucose tolerance test were not correlated with gestational diabetes mellitus(GDM)(aOR=1.038,95%CI:0.986-1.094,P=0.157;aOR=1.055,95%CI:1.000-1.113,P=0.051).The maternal weight gain of women with GDM during the 2nd,the 3rd,and the whole trimesters were lower than women without GDM respectively[3.0 kg(1.3-4.0 kg)vs 3.0 kg(2.0-5.0 kg),4.0 kg(2.0-6.0 kg)vs 6.0 kg(4.0-8.0 kg),9.0 kg(5.0-12.0 kg)vs 10.7 kg(7.5-15.0 kg);Z=-2.938,-6.352 and-4.104,all P<0.01].Conclusions In women with pre-pregnancy obesity,the first trimester is the critical window to control maternal GWG.GWG guidelines recommended by the Institute of Medicine could help to reduce the weight retention at six weeks postpartum,but couldn't reduce the risk of GDM,gestational hypertension,small/large for gestational age,or other major adverse pregnancy outcomes.