Infants of diabetic mothers: maternal and infant characteristics and incidence of hypoglcemia

Abstract

Background: Diabetes mellitus is the most common metabolic disease affecting women during pregnancy and is associated with adverse outcomes during the neonatal period, common one being hypoglycemia. The characteristics and incidence of hypoglycemia in infants of diabetic mothers (IDM) are not well reported in South Africa. Objectives: To describe the characteristics of IDM with or without hypoglycemia and to determine prevalence of hypoglycemia in IDM. Methods: Medical records of mothers, and their infants admitted with a diagnosis of IDM at gestational age ≥34 weeks and/ or birth weight ≥2000 grams and admitted at CHBAH from January 2012 to December 2013, were retrieved. Maternal characteristics, type and treatment of diabetes, infant characteristics and glucose measurements were captured for analysis. Results: A total of 234 IDM were admitted over this 2-year period and 207 met inclusion criteria. Median maternal age was 33 years. Seven percent of mothers had stillbirths and 14% had miscarriages in previous pregnancies. A total of 56% of mothers had gestational diabetes. Among infants, 54% were born preterm, 19% were large for gestational age (LGA) and 10% were macrosomic. Pre-gestational diabetic mothers had higher preterm births than gestational diabetic mothers (64% vs 48%, p=0.037). Hypoglycemia occurred in 39% of IDM, occurring within the first 3 hours of life in 85% of infants. There were no statistically significant differences in types of maternal diabetes and its treatment between hypoglycaemic and normoglycaemic infants, but hypoglycaemic infants were more likely to be LGA (28.2% vs 12.8%, p=0.009). Conclusion: Hypoglycemia is a common finding in IDM, presenting early in postnatal age. Only just over a quarter of hypoglycaemic infants are LGA. All IDM should be monitored for hypoglycemia, especially within the first 3 hours of life.