Impact of glycemic control on fetal birth weight in gestational diabetes

Objective: To assess the relationship between maternal glycaemic control and final newborn (NB) birth weight in patients with gestational diabetes (GD). Methods: A retrospective study was conducted on 214 singleton pregnancies with GD. Maternal characteristics, newborn outcomes and glycaemic control during pregnancy were analysed. GD was assessed by measurements of glycated haemoglobin (HbA1c) at different times during the third trimester (3T), fasting, pre-prandial, and 1 and 2 hour post-prandial capillary blood glucose (1hPP-2hPP). Results: The percentage of NB large for gestational age (LGA) was 9.9% (macrosomia 5.4%), with no differences between genders. Mothers with LGA NB had a higher weight and percentage of body fat before pregnancy (P < .05), more weight gain during pregnancy (P < .01), and required more insulin. In pregnancies with LGA NB, the mean third trimester HbA1c and mean HbA1c (P < .01), were higher, as well as 1hPP (P < .05), 2hPP (P < .01) blood glucose and mean capillary blood glucose (P < .05). The mean third trimester HbA1c and 2hPP blood glucoses were correlated with the fetal weight index (r = 0.22, P < .01, and r = 0.17, P < .05, respectively). Conclusions: Mothers with LGA NB have worse glycaemic control, despite having received a more intensive treatment. Treatment strategies should be implemented early during pregnancy, not forgetting maternal overweight treatment. HbA1c and 2hPP blood glucose are the only control parameters that correlated with NB weight in our group. (C) 2013 Sociedad Espanola de Diabetes. Published by Elsevier Espana, S.L. All rights reserved.