Pregnancy Weight Gain By Gestational Age In Women With Twin Pregnancies And The Relationship With Maternal And Neonatal Complications

Objective:To investigate optimal gestational weight gain(GWG)in dichorionictwin pregnancies and the relationship with maternal and neonatal complications.Methods:We designed a retrospective study for dichorionic twin pregnancies with normal gestational outcomes delivered at Peking University Third Hospital(Beijing,2011～2019).Hierarchical linear regression was used to express pregnancy weight gain as a smoothed function of gestational age according to pre-pregnancy BMI category.Charts of weekspecific values(4～39weeks)for the mean,standard deviation,and percentiles of maternal weight gain were created.We divided women with different preconception body mass index with distinct trimester-specific gestational weight gain(GWG)and total GWG and compared prenatal outcomes between different groups the through univariate and logistic regression.Results:The regression model fit well with the weight gain during different gestational weeks,which has found that the weight gain was slow before 13 weeks of gestation,and was close to uniform speed after 13 weeks of gestation,regardless of the pre-pregnancy BMI.The median and quartile(p25-p75)of weight gain were 17.6(15.2-20.3)kg,17.3(14.7-20.2)kg,and 15.7(12.9-18.8)kg at 37 weeks in the underweight,normal weight,and overweight and obese groups,respectively with the increase of pre-pregnancy BMI,the total GWG decreased(P=0.002)..Trimester-specific GWG speed and maternal and neonatal complications:Accelerating first trimester GWG speed increased the risk of GDM meanwhile,lower third trimester GWG speed decreased the risk of gestational hypertension and preeclampsia;Neonatal birth weight,which increased with GWG speed,was closely associated with second trimester GWG,those who exceeding the IOM range had lower risk of SGAConclusions:(1)The present study described maternal weight gain trajectory of twin pregnancies during gestation period,which provided evidence for weight management for twin pregnancies.GWG of twin pregnancy changes slowly in the first trimester of pregnancy and increases at a constant rate after the second trimester of pregnancy.Overweight and obese pregnancies have lower GWG.(2)Lower third trimester GWG speed decreased the risk of gestational hypertension and preeclampsia;Second trimester GWG speed had close relationship with fetal growth and neonatal birth weigh.