Analysis Of The Effect Of Pre-pregnancy Body Mass Index And Pregnancy Weight Gain On Pregnancy Outcome Of Pregnant Women With Twin Pregnancy

Objective:By analyzing the relationship between pre-pregnancy Body Mass Index(BMI),gestational weight gain(GWG)and pregnancy outcome,this paper obtained the suitable range of pregnancy weight gain of Chinese pregnant women with twin pregnancy,to provide the basis for the guidance of weight management and appropriate nutrition intake before and during pregnancy of twin pregnancy in China.Methods:A total of 585 subjects who delivered on January 1,2015 and December 31,2020 at the People’s Court of Jiangsu North were selected.And record a pregnant woman to be obtained from the electronic medical record system and the delivery of a newborn’s information,including pregnant women’s age,height,weight before pregnancy weight,labor and birth gestational age,pregnancy complications,such as gestational hypertension,preeclampsia,gestational diabetes,pregnancy with anemia,pregnancy with hypothyroidism,intrahepatic cholestasis disease,etc.)during pregnancy,delivery mode,neonatal birth weight and birth and other information.The subjects were divided into four groups according to their pre-pregnancy BMI: low body weight group(BMI<18.5 kg/m2),normal body weight group(18.5≤BMI < 24kg/m2),over recombinant(24≤BMI < 28 kg/m2)and obesity group(≥28 kg/m2).Calculate all pregnant women’s weight gain during pregnancy,twin pregnancy will gain weight P25～ P75 interval as the recommended weight range of this study,and according to the scope of object of study can be divided into 3 groups: group too little weight gain during pregnancy(pregnancy weight gain is less than the recommended range lower limit),pregnancy weight gain is suitable for group(gain is recommended range),excess weight gain during pregnancy group(the upper limit to gain significant to recommend).SPSS 26.0 was used to analyze the general conditions,delivery conditions,pregnancy complications and neonatal conditions of each group.Results:(1)The incidence of premature rupture of membranes(P=0.016)and anemia during pregnancy(P=0.000)in the normal weight group were lower than those in the other groups.The incidence of gestational diabetes mellitus(P=0.009)and gestational hypertensive disease(P=0.000)were higher in the overweight and obese groups than in the low and normal weight groups.There was no significant difference in the incidence of intrahepatic cholestasis during pregnancy and pregnancy with hypothyroidism among all groups.There was no significant difference in the incidence of premature infants among all groups.Pregnant women in the low weight and normal weight groups were more likely to deliver low weight infants than those in the hyper-reorganization and obesity groups(P=0.031),but the incidence of neonatal asphyxia in the hyper-reorganization and obesity groups was higher than that in the low weight and normal weight groups(P=0.013).The incidence of postpartum hemorrhage was higher in the low weight and obese groups than in the other two groups(P=0.016).The cesarean section rate among the four groups was not statistically significant(P=0.494).(2)The suitable weight gain range for pregnant women in this study was 12-18 kg,and the suitable weight gain range for twins in low weight group,normal weight group,super-recombinant group and obesity group was 14-17 kg,13-19 kg,12-18 kg and11-17 kg,respectively.The weight gain during pregnancy was positively correlated with the number of births and negatively correlated with the BMI level before pregnancy.The incidence of premature rupture of membranes(P=0.000),intrahepatic cholestasis during pregnancy(P=0.012)and anemia during pregnancy(P=0.002)were higher in women with insufficient weight gain during pregnancy than those with appropriate weight gain or excessive weight gain during pregnancy.The incidence of gestational diabetes mellitus in women with appropriate weight gain during pregnancy was lower than that in the other two groups(P=0.005).The incidence of hypertensive disease in pregnant women with excessive weight gain during pregnancy(P=0.004)was higher than that in the other two groups.The incidence of pregnancy with subclinical hypothyroidism(P=0.022)was highest in the group with appropriate weight gain during pregnancy.Pregnant women with excessive weight gain during pregnancy had lower probability of premature delivery(P=0.004)and low birth weight(P=0.000)than those with insufficient weight gain during pregnancy and those with appropriate weight gain during pregnancy.The cesarean section rate of women with appropriate weight gain during pregnancy(P=0.001)was higher than that of the other two groups.There was no statistical difference in the probability of neonatal asphyxia(P=0.094)and postpartum hemorrhage(P=0.342)among the three groups.Conclusion:The results of this study showed that BMI before pregnancy and weight gain during pregnancy were both related to maternal and infant outcomes,and the appropriate range of weight gain during pregnancy for pregnant women with twin pregnancy was 12-18 kg.The suitable weight gain range of low body weight group for twin pregnant women is 14～17kg,normal body weight group is 13～19kg,super-recombinant group is 12～18kg,obesity group is 11～17kg.In order to obtain a good maternal and infant outcome,the weight of twin pregnant women should be managed and given reasonable guidance before and during pregnancy.