Which newborns are at risk of hypoglycemia?

Newborns at Risk for Hypoglycemia

Newborns at risk for hypoglycemia include infants of diabetic mothers (IDM), preterm infants (less than 37 weeks' gestation), small for gestational age (SGA) infants (less than 10th percentile), low birth weight infants (less than 2500g), large for gestational age (LGA) infants (more than 90th percentile), high birth weight infants (more than 4500g), and post-term infants (more than 42 weeks' gestation). 1

Primary Risk Factors

According to the highest-scoring clinical practice guideline identified in a systematic review of neonatal hypoglycemia screening guidelines, the following infants should be considered at risk:

• Infants of mothers with diabetes (any type of diabetes) 1
• Preterm infants (less than 37 weeks' gestation) 1
• Small for gestational age (SGA) infants (less than 10th percentile) 1
• Low birth weight infants (less than 2500g) 1
• Large for gestational age (LGA) infants (more than 90th percentile) 1
• High birth weight infants (more than 4500g) 1
• Post-term infants (more than 42 weeks' gestation) 1

Incidence and Timing

• Approximately 26.3% of otherwise healthy newborns are eligible for hypoglycemia screening based on risk factors 1
• Up to 50% of at-risk infants develop low blood glucose concentrations 1
• Hypoglycemia is more frequently observed in the first 2 hours of life compared to later periods 2
• The incidence of hypoglycemia in identified at-risk infants ranges from 27% to 32% 3, 2

Additional Risk Considerations

• Male gender has been associated with an increased risk of hypoglycemia 2
• Twin delivery has been identified as a risk factor in some studies 4
• Gestational age is consistently the strongest predictor of hypoglycemia risk, with earlier gestational age associated with higher risk 4
• Neonatal infections have been associated with hypoglycemia 5

Clinical Implications

• Severe and prolonged hypoglycemia is associated with neurologic injury and long-term neurodevelopmental sequelae 1
• Hypoglycemia can lead to impaired visual-motor processing, executive functioning, and reductions in literacy and numeracy skills 1
• Hypoglycemia is often asymptomatic or presents with nonspecific clinical signs, making screening of at-risk infants crucial 1

Screening Approach

• At-risk infants should be monitored for at least 24 hours after birth 2
• Blood glucose monitoring should begin within the first 1-2 hours of life 4
• Screening should continue until plasma glucose concentration is >45 mg/dL on three consecutive occasions 3

Common Pitfalls and Caveats

• There is a lack of consensus between guidelines on the exact definition of at-risk infants 1
• Point-of-care glucometers may be inaccurate in detecting neonatal hypoglycemia 1
• Screening practices may disrupt establishment of breastfeeding 1
• Rapid rises in glucose concentrations following treatment may be associated with poorer neurodevelopmental outcomes 1
• Some "classical" risk factors may not be as strongly associated with early hypoglycemia as previously thought when analyzed in multivariate models 4

Special Considerations

• Early and continued breastfeeding augmented with oral dextrose gel may help prevent neuronal injury 6
• Infants with persistent hyperinsulinemia require aggressive management 6
• Approximately 2-10% of hypoglycemic newborns may require intravenous glucose treatment 3