Maternal Glucose and Neonatal Hypoglycemia in Pregnancy with Type 1 Diabetes: A Continuous Glucose Monitoring Cohort

Neonatal hypoglycemia (NH) is potentially life-threatening and can lead to long-term neurological sequelae. We retrospectively assessed the association between maternal glycemia in women with type 1 diabetes (T1D) and NH. Continuous glucose monitoring data from 60 mothers, alongside routine capillary blood glucose measurements from their neonates, were analyzed. The analyses used two clinically recognized thresholds for NH (<2.2 mmol/L and <2.6 mmol/L). In total, there were 25 neonates (41.7%) with NH <2.6 mmol/L and 19 neonates (31.7%) with NH <2.2 mmol/L. Neonates with NH <2.2 mmol/L were born at a lower gestational age (37.0 [35.9, 37.7] vs. 37.6 [37.0, 38.4] weeks, <i>P</i> = 0.019), a higher proportion was exposed to antenatal corticosteroids (31.6% vs. 7.3%, <i>P</i> = 0.014), and a higher proportion required admission to the neonatal intensive care unit (42.1% vs.12.2%, <i>P</i> = 0.009). Similar associations were observed for NH <2.6 mmol/L, although admission rates to the neonatal intensive care unit did not reach statistical significance. Mixed-effects logistic regression analysis identified percentage time above range (odds ratio [OR] 1.047, 95% confidence interval [CI] 1.007-1.087, <i>P</i> = 0.01) and percentage time in range (OR 0.951, 95% CI 0.914-0.989, <i>P</i> = 0.01) as significantly associated with NH <2.2 mmol/L. Our data suggest that careful optimization of glycemia early in pregnancy, rather than in the final trimester alone, may help minimize the risk of NH in infants born to mothers with T1D.