The Effects Of Maternal Glycemic Control On Neonatal Glucometabolic Disorders In Gestational Diabetes Mellitus Pregnancies

Objective:As the most common metabolic complication during pregnancy,the newborns of pregnant women with gestational diabetes mellitus（GDM）are prone to be glucometabolic disorders.Glycosylated hemoglobin（Hb A1c）and fructosamine（FMN）,reflecting the accumulated blood glucose levels,can be used to monitor the glycemic control in GDM pregnant women.In this study,the Hb A1c and FMN of GDM pregnant women before delivery were used as long-term（2-3 months）and short-term（2-3weeks）accumulated blood glucose exposures,respectively,to explore the effects of maternal glycemic control before delivery on neonatal glucometabolic disorders and birthweight in pregnant women with GDM.Methods:Pregnant women with GDM and their newborns who gave birth in our hospital from September 1,2018 to January 31,2021 were included in this study.The Hb A1c within 7 days and FMN within 3 days before delivery were collected as exposures.For being affected by plasma albumin（ALB）levels,the ratio of FMN to ALB(FMN/ALB*%,FMN_ALB)was used for correction to reflect the accumulated glucose levels of GDM pregnant women 2-3 weeks before delivery.The initial neonatal blood glucose levels,the blood glucose levels in the first 3 days and the birth weight of the newborns were recorded as the outcomes.Pearson correlation analysis and Spearman correlation analysis were used to analyze the correlations between the Hb A1c,FMN_ALB before delivery in GDM pregnant women and the initial neonatal blood glucose levels,respectively.A t-test was used to compare the initial neonatal blood glucose and the fluctuating blood glucose levels in the first 3 days of life between the different levels of Hb A1c in GDM pregnant women before delivery.Linear regression analysis was used to analyze the correlation between Hb A1c before delivery and neonatal birth weight;Multivariable logistical regression model was used to analyze the relationship between Hb A1c and FMN_ALB before delivery and neonatal glucometabolic disorders such as abnormal glucose metabolism,hypoglycemia,glucose intolerance,and large for gestational age（LGA）infants,which was expressed by odds ratio（Odds Ratios,OR）and 95%confidence interval（confidence interval,CI）.Results:（1）A negative correlation was observed between the Hb A1c of pregnant women with GDM before delivery and the initial neonatal blood glucose levels（r=-0.23,P<0.05）.However,no linear correlation was observed between the FMN_ALB of GDM pregnant women before delivery and the initial neonatal blood glucose levels.（2）Compared to the GDM pregnant women with Hb A1c<6%,the GDM pregnant women with Hb A1c≥6%had lower initial neonatal blood glucose levels（2.8±1.3 vs 3.5±1.4,t=2.77,P<0.01）,and higher neonatal blood glucose fluctuation in the first 3 days of life（3.7±1.8 vs2.8±1.3,t=-2.65,P<0.05）.（3）While the maternal Hb A1c increased by 0.1%before delivery,the risks of neonatal glucometabolic disorders and neonatal hypoglycemia increased 8%（a OR=1.08,95%CI 1.02-1.15）and 11%（a OR=1.11,95%CI 1.04-1.18）,respectively.However,the risk of glucose intolerance did not increase significantly（a OR=0.99,95%CI 0.93-1.07）.Compared to the newborns of the GDM pregnant women with Hb A1c<6%,the newborns in maternal Hb A1c≥6%had higher risk of neonatal glucometabolic disorders（a OR=2.87,95%CI 1.25-6.61）,higher risk of hypoglycemia（a OR=3.45,95%CI 1.49-8.00）,and higher risk of glucose intolerance（a OR=3.54,95%CI 1.06-11.82）.Using maternal FMN_ALB as exposure,the newborns in maternal FMN_ALB≥75th percentile group had higher risks in neonatal glucometabolic disorders（a OR=2.50,95%CI 1.35-4.66）,hypoglycemia（a OR=2.17,95%CI 1.16-4.09）,and glucose intolerance（a OR=1.74,95%CI 0.81-3.74）.Further in the sensitivity analysis,the newborns in maternal FMN_ALB≥90^th percentile group had higher risks in neonatal glucometabolic disorders（a OR=5.66,95%CI 2.17-14.81）,hypoglycemia（a OR=3.71,95%CI 1.48-9.31）,and glucose intolerance（a OR=2.15,95%CI0.78-5.96）.（4）While the Hb A1c increased by 0.1%in GDM pregnant women before delivery,the birth weight and the risk of LGA infants increased 25g（95%CI 17-33,P<0.001）and 11%（OR=1.11,95%CI 1.05-1.17）in the newborns,respectively.Compared to the newborns of the GDM pregnant women with Hb A1c<6%,the newborns in maternal Hb A1c≥6%had higher risk of LGA infants（OR=4.13,95%CI 1.83-9.30）.However,the FMN_ALBvalue of GDM pregnant women before delivery were not a good predicting indicator for the risk of LGA infants.Conclusions:（1）The newborns of GDM pregnant women with poor glycemic control before delivery had higher risks of neonatal glucometabolic disorders.（2）Both the Hb A1c and FMN_ALB of GDM pregnant women before delivery are good predicting indicators for neonatal glucometabolic disorders.However,for FMN_ALBcan only reflect the short-term accumulated blood glucose levels,it is less useful to predict neonatal glucometabolic disorders than Hb A1c.（3）The Hb A1c of GDM pregnant women before delivery was associated with the birthweight and the risk of LGA in the newborns.