Impact of gestational weight gain and pre-pregnant body mass index on pregnant outcomes / 中华围产医学杂志

ABSTRACT

Objective To evaluate the effects of gestational weight gain(GWG) in different prepregnant body mass index (BMI) women on perinatal outcomes and to provide evidences for gestational weight management protocol.Methods Totally,2409 healthy singleton pregnant women accepted regular prenatal examinations in Nanjing Drum Tower Hospital from January 2009 to April 2010 were recruited in this study.They were divided into three groups according to pre-pregnant BMI,which were low BMI group (BMI＜18.5),normal BMI group (BMI 18.5-) and high BMI group (BMI≥24.0).According to GWG,the difference between pre-delivery maximal weight and prepregnant weight,the low and normal BMI women were divided into ＜10 kg,10 kg-and ≥15 kg GWG subgroups,and the high BMI women were divided into ＜5 kg,5 kg-,10 kg and ≥15 kg GWG subgroups.Data including gestational age,delivery modc,newborns' birth weight,Apgar score and incidences of gestational complications,such as hypertensive disorders complicating pregnancy (HDP),gestational diabetes mellitus (GDM),macrosomia,fetal growth restriction (FGR) and preterm birth,were recorded.Analysis of variance,Student-Newman Keuls,Chi-square test and Fisher exact test were applied for statistics.Results (1) Among the 2409 women,the percentages of low,normal and high BMI groups were 18.5％ (n=445),69.9％ (n=1685) and 11.6％ (n=279),respectively.The incidences of HDP,GDM,macrosomia and caesarean delivery in high BMI group were 12.9％ (n=36),17.9％ (n=50),13.6％ (n=38) and 52.3％ (n=146),respectively,higher than those in low BMI group [3.4％ (n=15),4.3 ％ (n=19),3.8％ (n=17) and 25.8％(n=115),x2 =23.8,37.1,23.5 and 50.2,P＜0.05] and those in normal BMI group [5.5％ (n=92),7.8％ (n=132),7.8％ (n=132)and 31.6％ (n=532),x2=21.8,29.0,10.1 and 3.4,P＜0.05].(2) In normal BMI group,the rates of FGR and preterm birth in GWG ＜10 kg subgroup were 3.5％ (4/115) and 8.7％ (10/115),higher than those in GWG 10 kg-subgroup [0.7％(4/548) and 3.3％(18/548),x2=6.0 and 6.9,P＜0.05] and GWG ≥15 kg subgroup [(0.8 ％ (8/1022) and 3.6％ (37/1022),x2=7.2 and 6.7,P＜0.05].The rates of macrosomia and cesarean delivery in GWG ≥15 kg subgroup were 10.7％ (109/1022) and 34.5％ (353/1022),higher than those in GWG＜10 kgsubgroup [3.5％ (4/115) and 32.2％ (37/115),x2=6.0 and 63.0,P＜0.05] and GWG 10 kg subgroup [3.5％ (19/548) and 25.9％ (142/548),x2=24.7 and 31.0,P＜0.05].(3) In high BMI group,the incidences of all pregnancy complications and perinatal outcomes did not show statistical significance among the four GWG subgroups (P＞0.05).Conclusions High prepregnant BMI is a high risk factor of pregnancy complications.It is suggested that normal BMI women should control GWG at 10-15 kg to lower the incidences of pregnancy complications.