孕前体重指数及其孕期增加对妊娠结局的影响

Effects of prepregnancy BMI and increasing range of BMI during pregnancy on pregnancy outcomes

目的:定量评价孕前体重指数及孕期体重指数增加情况对我国北方孕妇妊娠结局的影响。方法:收集2007～2009年在沈阳3家医院分娩的3741名单胎妊娠初产妇,按照孕前体重指数(BMI)分为4组:低体重组(BMI<18.5kg/m2)、正常体重组(18.5kg/m2≤BMI<24kg/m2)、超重组(24kg/m2≤BMI<28kg/m2)和肥胖组(BMI≥28kg/m2)。按照孕期BMI增加情况分为3组:A组(BMI增加<4)、B组(BMI增加4～6)、C组(BMI增加>6)。Logistic回归评估不良妊娠结局的危险度,结果用RR和95%CI表示。结果:①和正常体重组相比,孕前低体重、超重和肥胖组的孕妇患子痫前期的RR分别为0.53(95%CI0.29～0.97)、2.84(95%CI2.05～3.94)和5.35(95%CI3.47～8.49);患妊娠期糖尿病的RR分别为0.35(95%CI0.16～0.78)、3.40(95%CI2.44～4.75)和4.95(95%CI2.91～7.06);剖宫产和出生大于胎龄儿(LGA)的风险也随孕前体重的增加而增加。②和B组相比,C组增加了子痫前期(RR1.85,95%CI1.40～2.44)、妊娠期糖尿病(RR1.39,95%CI1.05～1.86)、剖宫产(RR1.37,95%CI1.15～1.63)及出生LGA(RR1.98,95%CI1.44～2.73)的相对危险性,但降低了出生SGA的风险。A组降低了子痫前期、剖宫产和出生LGA的风险,但增加了早产(<34周)和出生SGA的风险。结论:孕前体重指数过高及孕期体重指数增加过度可以明显增加孕妇子痫前期、妊娠期糖尿病和剖宫产的风险。应加强健康教育,适度控制孕期体重,合理营养减少肥胖,对预防妊娠并发症,改善妊娠结局是有必要的。

Objective：To evaluate the effects of prepregnancy BMI and increasing range of BMI during pregnancy on pregnancy outcomes among women in north of China quantitatively.Methods：3 741 primiparous women of single pregnancy who delivered in three hospitals of Shenyang from 2007 to 2009 were selected and divided into four groups according to prepregnancy BMI：low body weight group （BMI〈18.5 kg/m^2）,normal body weight group （18.5 kg/m^2≤BMI〈24 kg/m^2）,overweight group （24 kg/m^2≤BMI28 kg/m^2） and obese group （BMI ≥28 kg/m^2）; while at the same time,they were divided into three groups according to increasing range of BMI during pregnancy：A group （increasing range of BMI during pregnancy〈4）,B group （increasing range of BMI during pregnancy=4-6） and C group （increasing range of BMI during pregnancy〉6）.The risk degree of adverse pregnancy outcomes was evaluated by logistic regression analysis,the results were represented by RR and 95%CI.Results：Compared with normal body weight group,the RR of preeclampsia in low body weight group,overweight group and obese group were 0.53 （95%CI 0.29,0.97）,2.84 （95%CI 2.05,3.94） and 5.35 （95%CI 3.47,8.49）,respectively; the RR of gestational diabetes mellitus were 0.35 （95%CI 0.16,0.78）,3.40 （95%CI 2.44,4.75） and 4.95 （95%CI 2.91,7.06） ,respectively; the risks of cesarean section and large for gestational age infants increased with rising prepregnancy BMI.Compared with B group,C group had increased risks of preeclampsia （RR1.85; 95%CI 1.40-2.44）,gestational diabetes mellitus （RR 1.39; 95%CI 1.05-1.86）,cesarean section （RR 1.37; 95%CI 1.15-1.63） and large for gestational age infants （RR 1.98; 95%CI 1.44-2.73）,but the risk of small for gestational age infants decreased; the risks of preeclampsia,cesarean section and large for gestational age infants in A group decreased,but the risks of premature delivery （〈34 gestational weeks） and small for gestational age infants increased.Conclusion：The high prepregnancy BMI and increasing range of BMI during pregnancy can increase the risks of preeclampsia,gestational diabetes mellitus and cesarean section; in order to prevent pregnancy complications and improve pregnancy outcomes,it is necessary to enhance health education,control body weight during pregnancy,reasonable nutrition and reduce obesity.