From the Guidelines
Neonatal hypoglycemia is primarily caused by maternal factors such as diabetes, prematurity, small for gestational age (SGA), and large for gestational age (LGA) infants, particularly those born to diabetic mothers, as well as perinatal stress and congenital metabolic disorders, as supported by recent studies 1, 2. The main causes of neonatal hypoglycemia can be broken down into several key factors:
- Maternal factors, including diabetes, which can lead to fetal hyperinsulinemia and subsequent hypoglycemia after birth when the maternal glucose supply is removed 1
- Prematurity, as premature infants have limited glycogen stores and immature gluconeogenesis pathways 1
- Small for gestational age (SGA) or intrauterine growth restriction (IUGR) babies, who have reduced glycogen reserves 1
- Large for gestational age (LGA) infants, particularly those born to diabetic mothers, who often have hyperinsulinemia 1, 2 Other causes include:
- Perinatal stress, such as asphyxia, sepsis, or hypothermia, which increases glucose consumption 1
- Congenital metabolic disorders affecting glucose metabolism, such as fatty acid oxidation disorders 2
- Endocrine disorders like congenital hypopituitarism or hyperinsulinism 1, 2
- Delayed feeding after birth, which can contribute to hypoglycemia as newborns transition from continuous maternal glucose supply to intermittent feeding 1 It is essential to note that targeted screening is based on risk factors for transient hypoglycemia, and may not reliably detect infants with genetic causes of hypoglycemia, such as fatty acid oxidation disorders 2. Therefore, it is crucial to consider these factors when assessing the risk of neonatal hypoglycemia and to implement appropriate management strategies, including early feeding, glucose monitoring, and intravenous glucose administration if necessary, to maintain blood glucose above 45-50 mg/dL (2.5-2.8 mmol/L) 1, 2.
From the Research
Main Causes of Neonatal Hypoglycemia
The main causes of neonatal hypoglycemia can be attributed to several factors, including:
- Prematurity: Preterm neonates are uniquely predisposed to developing hypoglycemia due to their limited glycogen and fat stores, inability to generate new glucose using gluconeogenesis pathways, and higher metabolic demands 3.
- Intrauterine growth restriction: Small for gestational age (GA) and intra-uterine growth restricted neonates are especially vulnerable to hypoglycemia due to their lack of metabolic reserves and associated co-morbidities 3.
- Maternal diabetes: Hypoglycemia is commonly associated with maternal diabetes, as the high glucose levels in the mother's blood can lead to an increase in insulin production in the fetus, causing hypoglycemia after birth 4.
- Hyperinsulinism: Hypoglycemia due to hyperinsulinism, especially genetic causes, can lead to brain injury and neurodevelopmental impairment 5.
- Limited glycogen and fat stores: Preterm neonates have limited glycogen and fat stores, making them more susceptible to hypoglycemia 3.
Risk Factors
Other risk factors for neonatal hypoglycemia include:
- Asymptomatic high-risk newborns: Screening for hypoglycemia is recommended in asymptomatic high-risk newborns, as they are at increased risk of developing hypoglycemia 6.
- Symptomatic newborns: Symptomatic newborns, such as those with seizures, flaccid hypotonia, and apnea, are at high risk of developing hypoglycemia and require prompt treatment 7.
- Inability to generate new glucose: Preterm neonates are unable to generate new glucose using gluconeogenesis pathways, making them more susceptible to hypoglycemia 3.