Blood Glucose Levels and Characteristics of Hypoglycemia in Low Birth Weight Neonates

Abstract

Introduction: Low birth weight (LBW) neonates comprising of preterm and small for gestational age (SGA) are at risk of hypoglycemia. Hypoglycemia as such in LBW neonates is not well characterized. We aimed to study the blood glucose levels of these neonates and characterise the hypoglycemia. Methods: Blood glucose levels in singleton neonates with birth weight between 1500 gm and 2499 gm were studied prospectively. Glucose levels were assessed at six hour intervals in the first 48 hours of life and extended if indicated. Glucose level ≤ 45 mg/dL in the first 24 hours and < 50 mg/dL thereafter was considered hypoglycaemia. Results: A total of 320 among 3822 neonates satisfied inclusion criteria; 104 had at least one low glucose reading with an incidence of hypoglycaemia of 32.5%. Preterm neonates constituted 158 (49.4%) and SGA 76 (23.8%). Mean blood glucose values were lowest in the first hour of life (60.1 ± 17.2 mg/dL). Incidence of hypoglycemia was highest within one hour of life followed by day two of life (16.3% and 11.6% respectively). About 86 (82.6%) neonates were asymptomatic. Overall, 75% of neonates had a single episode of hypoglycemia and 25% had a recurrence. Hypoglycaemia was noted in 31.8% of neonates born to diabetic mothers, mostly in the first hour (57.1%). Other risk factors for hypoglycemia included intrapartum fluids, birth weight < 2000 g and polycythemia. Conclusions: About a third of LBW neonates had hypoglycemia; mostly on the first hour and day one of life. Asymptomatic nature of hypoglycaemia in the large majority and recurrent hypoglycemia in 25% cases warrants glucose monitoring in this subgroup.