Increased risk of admission to neonatal intensive care unit in neonates born to mothers with pregestational diabetes.

The purpose of this study was to describe how maternal diabetes impacts admission to the neonatal intensive care unit to support healthcare professionals when counselling patients. The primary outcome was admission rates. A retrospective observational cohort study of 25,238 births was conducted at an Irish tertiary maternity hospital from January 2018 to December 2020. Cases of pregestational and gestational diabetes were examined for neonatal intensive care admission outcomes. R statistical analysis software was used. There were 3905 live neonates born between 34 and 42 weeks to mothers with diabetes (N = 67 type 1 diabetes, N = 60 type 2 diabetes, N = 3712 gestational diabetes, N = 5 mature onset diabetes, excluded N = 61). There was a statistically significant difference in mean gestational age: 37 + 1 (weeks/days) (95% CI 36 + 6-37 + 4), 38 + 1 (95% CI 37 + 5-38 + 3, p = 0.0019), and 39 (95% CI 38 + 6-39 + 1, p ≤ 0.001) in type 1, type 2, and gestational diabetes cohorts. Admission rate was 13.4% with significant differences between the subgroups: 41.8% [95% CI 2.33-4.58, RR 3.32], 31.1% [95% CI 1.55-3.50, RR 3.89], and 12.5% [95% CI 0.12-0.14, RR 0.133] in type 1, type 2, and gestational diabetes cohorts. A higher percentage of mothers with pregestational diabetes (42.9% and 31.5%) were discharged before their infants, versus 21.2% of gestational diabetes.

Conclusion: Neonates of mothers with pregestational diabetes have a significantly higher admission rate. The type 1 diabetes cohort were born earlier and had higher birth weight centiles. Hypoglycaemia remains a significant risk for all subgroups.

What is known: • Infants of mothers with T1DM are born earlier and have higher morbidity rates compared to infants of mothers with T2DM or GDM.

What is new: • A higher proportion of neonates born to T2DM mothers were admitted due to severe/refractory hypoglycemia, however hypoglycemia was detected after admission in many neonates transferred to NICU for other reasons. It remains a significant risk and requires vigilance of all neonates born to mothers with pregestational or gestational diabetes. • Mothers with pre-gestational diabetes were more likely to be discharged home while their infant remains in NICU.