Association Between Gestational Weight Gain And Perinatal Outcomes In Twin Pregnancies: A Cohort Study

Objective:To detect the association between gestational weight gain and perinatal outcomes in twin pregnant women.To analysis the association between participant's baseline BMI,weight change ratio(kg/wk)and perinatal outcomes in twin pregnancies.To examine the applicability in Chinese twin pregnancies according to the 2009 US IOM recommendations of gestational weight gain.Methods:Women were recruited at first examination,maternal weight was measured by trained research nurses at each clinic visits and the perinatal outcomes were documented.They were divided into three groups according to baseline BMI(kg/m2):underweight(BMI<18.5),normal(18.5?BMI<24.0),and overweight(24.0?BMI<28.0).Participant's weight change ratio(kg/wk)in the second trimester(12?20 and 20?28 wk)and third trimester(28?delivery)and total weight gain(kg)during entire gestation were calculated.They were divided into four groups according to weight gain quartiles.Baseline BMI and weight gain quartiles were used in analyses of birth outcome and mobidity of pregnancy complications.Results:Morbidity of GDM and GHP significantly difference across the baseline BMI groups.Incidence of GDM significantly differed between groups categorized as 20 to 28 weeks weight gain quartiles and incidence of PE significantly differed between groups categorized as 28 to delivery weight gain quartiles.Weight gain during 12 to 20 weeks and 20 to 28 weeks,and total gestational weight gain were significantly positively correlated with twin birth weight.Incidence of PTB and PROM were significant different between groups categorized as total weight gain quartiles.Finally,linear regression analysis showed that weight gain during 12 to 20,20 to 28 weeks and total weight gain were significantly positively correlated with twin birth weight,logistic regression model showed that weight gain during 28 weeks to delivery was independent risk factor for the development of PE,total gestational weight gain was independent risk factor for the incidence of PTB.The morbidity of gestational hypertension was positive correlate with gestational weight gain.The gestational age at delivery was 35.29 ± 2.25 wk in low GWG group,36.32±1.33 wk in adequate GWG group and 36.50±0.94 wk in high GWG group,the difference was statistically significant.Very preterm birth and very premature rupture of membranes were negative correlate with gestational weight gain.Conclusion:Total maternal weight gain was an independent risk factor for the incidence of preterm birth,maternal weight gain before late pregnancy have an impact on twin birth weight.Maternal weight gain during 28 weeks to delivery was significantly positively correlated with the morbidity of preeclampsia.In twin pregnancies,gestational weight gain conforming to the recommendation of the IOM guideline was beneficial to reduce the incidence of pregnancy complications and to gain a favorable delivery outcome.