Breastfeeding and Its Impact on Glucose Trends and Hypoglycaemia Risk in At-Risk Neonates: A Prospective Observational Study.

Introduction: Neonatal glucose regulation undergoes a rapid transition after birth, with glucose levels declining within the first few hours before stabilising. At-risk neonates, including those who are preterm, small-for-gestational-age (SGA), large-for-gestational-age (LGA), or born to mothers with diabetes or obesity, face an increased risk of hypoglycaemia. Early feeding is recommended to support glucose homeostasis, yet the impact of feeding type on glucose trends and hypoglycaemia risk remains unclear. This study aims to compare glucose trajectories and hypoglycaemia incidence between exclusively breastfed and formula-fed neonates.

Methods: This prospective observational cohort study was conducted at KK Women's and Children's Hospital, Singapore, from December 16, 2019, to March 16, 2020. A total of 192 at-risk neonates were included. Blood glucose concentrations were measured at 2, 6, 12, 18 and 24 h of life. Hypoglycaemia was defined as blood glucose concentration < 3.0 mmol/L, with an additional threshold of < 2.6 mmol/L. The area under the curve (AUC) for glucose concentrations was calculated, and multivariable logistic regression was performed to assess hypoglycaemia risk.

Results: Exclusively formula-fed neonates exhibited higher glucose levels at 6, 12 and 24 h compared to breastfed neonates (p = 0.030, p = 0.004, and p < 0.001, respectively), with a greater cumulative glucose exposure (AUC: 85.1 vs. 80.5 mmol/L-hour). However, the overall hypoglycaemia incidence (< 3.0 mmol/L) was similar between feeding groups (14.7% vs. 11.1%, p = 0.615). Adjusted logistic regression showed no significant association between feeding type and hypoglycaemia risk.

Discussion: Despite overall lower glucose levels in breastfed neonates, hypoglycaemia risk remained comparable between feeding groups. These findings support prioritising breastfeeding in at-risk neonates. Further research is needed to evaluate the long-term metabolic implications of early feeding practices.