The Association Of Gestational Weight Gain And Adverse Pregnancy Outcomes In Women Complicated By Hyperglycaemia

Background:Gestational diabetes mellitus(GDM)is diagnosed during the 2nd or 3rd trimester of pregnancy without overt diabetes prior to conception,which rate had culminated in women of reproductive stage.Currently,the recommendation forGWG,according to the Institute of Medicine(IOM),was differed according to different pre-pregnancy BMI.However,IOM target are commonly adopted by women with all statures.It is unclear that whether the IOM targets might be applicable for pregnancies with GDM.Furthermore,the relative effects of specific-trimesterGWG on adverse perinatal outcomes is still unknown for pregnancies with GDM.Examination of the effect ofGWG in GDM status on pregnancy outcomes is a critical question.The purpose of this study was to address the association ofGWG and adverse pregnancy outcomes in GDM.Furthermore,we sought to determine whether a stricterGWG target might be applied to women with GDM,for the purpose of reducing the prevalence of adverse outcomes.We further explore the risk of perinatal adverse outcomes in pre-gestational type 1 diabetes mellitus(T1DM)compared to gestational diabetes mellitus(GDM)and pregnancy of normal glucose tolerance(NGT).Methods:A retrospective cohort study of 1138 women with singleton normal glucose tolerance(NGT)and 1200 GDM pregnancies who had delivered infants between January 2016 and December 2017 was conducted at Drum Tower Hospital Affiliated to Nanjing University Medical School in China.According to IOM target pregnancies of each pre-gestational BMI levels who gained appropriateGWG were classified to aGWG group,who gained inadequateGWG to inadequateGWG group(iGWG)and who gained excessiveGWG to excessiveGWG group(eGWG).To determine whether a modified target may improve the adverse outcomes for women with GDM,we undertook several analyses using differentGWG targets.We conducted subtractions of either upper limit or both upper and lower limit of original IOMGWG target for each pre-gravid BMI classes.The groups of modifiedGWG target derived by:(1)IOM-1group:upper limit of IOM target minus 1kg;(2)IOM-2 group:upper IOM target minus2kg;(3)IOM-1-1 group:both upper and lower limit of IOM target minus 1kg;(4)IOM-2-2 group:both upper and lower limit of IOM target minus 2kg.Neonatal and maternal adverse perinatal outcomes were documented.We calculated partial PARs(partial population attributable risk)for being GDM or gaining eGWG in pregnancy.We further evaluate relative contributions of specific-trimesterGWG to the delivery of large for gestational age(LAG).Based on neonatal birthweight,infant sex and weeks of delivery all infants born by pregnancies with GDM were separated into LGA group,small for gestational age(SGA)group and appropriate for gestational age(AGA)group.Semipartial correlation were used to calculate the relative contributions of 1^st-trimesterGWG(from pre-conception to 1^st antenatal visit),2^nd-trimesterGWG(from 1^stantenatal visit to the conduction of 75g oral glucose tolerance test)and 3^rd-trimesterGWG(from the conduction of 75g OGTT to the delivery)to the delivery of LGA.A total of 71 pre-gestational T1DM,1200 GDM and 1200 NGT from November 2011 and December 2017 were included.Three groups were matched of maternal age,parity and pre-gravid body mass index(BMI).Data regarding demographics,obstetric and perinatal outcomes were extracted from the hospital discharge database.Result:Relative to aGWG NGT,adjusted OR for LGA was 1.47 for eGWG NGT,1.42for aGWG GDM,and 2.70 for eGWG GDM,after controlling for maternal age,parity,gravidity and infant sex.Likewise,when adjusted for the same covariates as above,the adjusted OR for macrosomia in eGWG NGT was 2.06,aGWG GDM was 1.66,and eGWG GDM was 3.33 compared with aGWG NGT.For GDM pregnancies gaining aGWG according to modifiedGWG targets(IOM-1,IOM-2,IOM-1-1 and IOM-2-2)the prevalence of LGA delivery was significantly lower than aGWG GDM defined by IOM target.Similarly,relative to aGWG GDM according to IOM target,aGWG GDM defined by IOM-2,IOM-1-1 and IOM-2-2 had lower rates of macrosomia delivery.Relative to aGWG NGT,aGWG GDM pregnancies according to modifiedGWG targets(IOM-1,IOM-2,IOM-1-1 and IOM-2-2)had no increased risks of LGA and macrosomia delivery after adjusting covariates.All trimesterGWG including 1^st-trimesterGWG,2^nd-trimesterGWG and 3^rd-trimesterGWG were positively associated with birthweight.Pre-pregnancy BMI had the biggest contribution to the delivery of LGA(13%).And 1^st-trimesterGWG,2^nd-trimesterGWG and 3^rd-trimesterGWG contributed for 10,9,and 8%to the prevalence of LGA,respectively.Relative to the pregnancies without diabetes,both pregnancies with T1DM and GDM encountered increasing risk of polyhydramnios,pre-eclampsia,preterm delivery and cesarean section.The rate of above pregnancy outcomes in T1DM were even significantly higher than GDM(p<0.05).The babies delivered by women with T1DM and GDM had higher risk to be large for gestational age(LGA),macrosomia and admitted to neonatal intensive care unit(NICU)compared to NGT pregnancies.Besides infants delivered by T1DM were more tend to weight less than 2.5kg and have neonatal jaundice relative to NGT.Compare with GDM pregnancies,T1DM had higher rate of small for gestational age(SGA)infant delivery,birthweight less than 2.5kg and their babies had increasing prevalence of neonatal jaundice and NICU admission(p<0.05).Conclusion:MaternalGWG had relationship with adverse perinatal outcomes.However,even for aGWG GDM there was still significantly higher risk of LGA and macrosomia delivery relative to aGWG NGT.Furthermore,compared with original IOM target,restrictingGWG according to a more rigorous range was associated with improved pregnancy outcomes for women with GDM.1^st-trimesterGWG has the greatest impact on the occurrence of LGA in pregnant women with GDM,but even so,it is still necessary to control weight gain after the diagnosis of gestational diabetes in this population.Women with T1DM have considerably increased risks of adverse pregnancy outcomes,which appear more prevalent than the pregnancy outcomes in women with GDM.Further studies are needed to explore whether lifestyle management according to more stringentGWG target could improve perinatal outcomes for women with hyperglycaemia.