Does HgA1C Correlate With Birth Weight and Other Neonatal Outcomes in Gestational Diabetics? [28K

Abstract

INTRODUCTION: Gestational diabetes has been associated with adverse neonatal outcomes. The objective of the study was to determine if third trimester glucose control, determined by HgA1C, is correlated with birth weight or other adverse neonatal outcomes. METHODS: A prospective cohort trial was performed at a single institution from 2/2013 to 1/2016. Gestational diabetics were enrolled and had a HgA1C within 4 days postpartum as an indicator of glucose control in the third trimester. Exclusion criteria included multiple gestations, delivery before 34 weeks, and chronic steroid use. Fetal growth was determined by a ratio of observed to expected birth weight (90th %) for gestational age, (O/E BW ratio). Linear regression analysis determined association between HgA1C and O/E BW ratio. Wilcoxon rank sum test assessed the correlation between HgA1C and neonatal intensive care unit (NICU) admission, respiratory distress syndrome (RDS), hypoglycemia, and hyperbilirubinemia. RESULTS: Sixty-eight women enrolled had an immediate postpartum HgA1C drawn. Mean pre-pregnancy BMI was 29 +/-6 kg/m2 and mean HgA1C was 5.6% +/- 0.6%. There was a statistically significant correlation between HgA1C values and O/E BW ratio, r= 0.509, p < 0.001. The optimal HgA1C cutoff, corresponding to an O/E BW ratio of 1, was 5.77%. HgA1C did not differ among neonates admitted to the NICU, or with a diagnosis of RDS, hypoglycemia, or hyperbilirubinemia. CONCLUSION: In a cohort of well-controlled gestational diabetic women with a normal mean HgA1C, a positive correlation was found between HgA1C and O/E BW ratio. Strict diabetic control with HgA1C less than 5.77% may prevent fetal overgrowth.