Neonatal chemical hypoglycemia in newborns from pregnancies complicated by type 2 and gestational diabetes mellitus – the importance of neonatal ponderal index

OBJECTIVE: To determine the frequency and risk factors associated with neonatal chemical hypoglycemia in neonates of mothers with type 2 diabetes and gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: A retrospective cohort study of women with type 2 diabetes or GDM and their singleton neonates. The primary outcome measure was the presence of neonatal chemical hypoglycemia (capillary plasma equivalent glucose <45 mg/dl) within 1 h of birth. Statistical methods included bivariate and multivariate analyses. RESULTS: 242 mother infant dyads were identified. Sixty-eight (28%) were treated with diet, 110 (46%) with glyburide, and 64 (26%) with insulin. The incidence of neonatal chemical hypoglycemia was 18% (44/242). The incidence was significantly higher in those requiring pharmacotherapy (25% vs. 3%, p < 0.001). The frequency of neonatal chemical hypoglycemia between the glyburide and insulin-treated pregnancies did not differ significantly (23% vs. 27%, p = 0.58). The frequency of neonatal chemical hypoglycemia was statistically associated with birth weight, macrosomia and ponderal index (p < 0.001). Neonatal ponderal index was the strongest predictor of hypoglycemia (adjusted Odds ratio 5.59). CONCLUSION: Neonatal chemical hypoglycemia occurs more frequently in infants from women with type 2 diabetes and GDM treated with glyburide or insulin. An increased neonatal ponderal index is a strong predictor of significant neonatal chemical hypoglycemia.