Aim: To describe the continuous glucose monitoring (CGM) profiles of type 1 diabetes (T1D) offspring in the early neonatal period and its association with maternal intrapartum glucose control. Methods: A prospective observational study of T1D pregnant women and their neonatal offspring. Women had a CGM sensor inserted 2-3 days prior to delivery. Infants had a masked CGM sensor inserted as soon as possible following delivery. Maternal glycaemic outcomes were time-in-target (70-140 mg/dL [3.9-7.8 mmol/L]), hyperglycaemia >140 mg/dL (7.8 mmol/L) and mean CGM glucose during the 24 hours preceding delivery. Neonatal outcomes included lowest recorded blood glucose concentration, and CGM measures (glucose 140 mg/dL (7.8 mmol/L), and 9 (9) % time < 70 mg/dL (3.9 mmol/L) with mean (SD) CGM glucose 113 (9) mg/dL (6.3 [0.7] mmol/L). 15 infants (93.8%) had ≥1 blood glucose concentration < 47 mg/dL (2.6 mmol/L) and five had ≥1 blood glucose concentration < 18 mg/dL (1.0 mmol/L). The mean infant CGM glucose on days 1, 2, and 3 of life was 63 (14), 67 (13), 76 (11) mg/dL (3.5 [0.8], 3.7 [0.7], and 4.2 [0.6] mmol/L). Four infants (25%) spent more than 50% time with CGM glucose levels < 47 mg/dL (2.6 mmol/L) on day 1. Conclusions: CGM detected widespread neonatal hypoglycaemia, even among mothers with good intrapartum glucose control
