In addition to this post, please see and review Neonatal Glucose Monitoring Dx and Rx Flow Charts From CHOP.
This podcast is designed to give you an overview of neonatal hypoglycemia. Listeners will learn about infants at risk, signs and symptoms, screening, and the diagnosis and management of neonatal hypoglycemia. This podcast has been developed by Carina Lauzon, a medical student at the University of Alberta with Dr. Marc-Antoine Landry, a neonatologist at the Royal Alexandra Hospital in Edmonton, Alberta.
And here are excerpts:
This PedsCases podcast is designed to give an organized approach to
neonatal hypoglycaemia, the most common metabolic problem in neonates and the leading cause of admissions to the neonatal intensive care unit.
Risk factors/Causes for Neonatal Hypoglycaemia
The most important risk factors for neonatal hypoglycaemia include:
- being small for gestational age (SGA, <10th percentile) or large for gestational age (LGA, >90th percentile),
- intrauterine growth restriction (IUGR),
- being born prematurely (<37 weeks),
- and being the infant of a diabetic mother.
Infants who suffer from sepsis and infants of mothers with eclampsia or
chorioamnionitis are also at an increased risk for hypoglycaemia.
The two most common causes of neonatal hypoglycaemia are excess insulin production and inadequate glycogen stores: in both of these situations, gluconeogenesis is impaired.
Excess insulin production, or hyperinsulinism, is the most common cause of neonatal hypoglycaemia.
Hyperinsulinism frequently occurs in infants of diabetic mothers and in
macrosomic infants (infants who weigh over 4kg at birth): . . .
Inadequate glycogen stores are another common cause of neonatal hypoglycaemia. Infants who are born prematurely (<37 weeks), are small for gestational age (SGA) or have intrauterine growth restriction may have low hepatic glycogen stores, low muscle stores, and low lipid stores to be used as substrates for gluconeogenesis and ketogenesis.
Similarly, infants who experience perinatal asphyxia or starvation may deplete their glycogen stores and therefore be unable to produce glucose through gluconeogenesis.
Other less common causes of neonatal hypoglycaemia include increased glucose use (which can happen as a result of hypothermia, sepsis, polycythemia, growth hormone deficiency, or cortisol deficiency), inborn errors of metabolism, adrenal insufficiency, liver disease, poisonings or drugs, and systemic disease.
Signs and Symptoms
The clinical presentation of neonatal hypoglycaemia can range from a completely asymptomatic infant to severe central nervous system and cardiopulmonary disturbances.
There are two general categories of symptoms of neonatal hypoglycaemia:
- neurogenic symptoms
- and neuroglycopenic symptoms.
The neurogenic symptoms happen as a result of sympathetic nervous system stimulation in response to hypoglycaemia. They are the first symptoms to appear, occurring at higher blood glucose concentrations than the neuroglycopenic symptoms.
The neurogenic symptoms include:
- temperature instability,
- and vomiting.
The neuroglycopenic symptoms happen as a result of decreased glucose delivery to the brain and include:
- episodes of cyanosis,
- a weak or high-pitched cry,
- and coma that may lead to death if the hypoglycaemia is not corrected.
Severe, recurrent neonatal hypoglycaemia can cause permanent brain damage, . . .
Because neonatal hypoglycaemia can lead to severe consequences, it is important to know which babies should be screened.
For the purposes of screening, the Canadian Pediatric Society recommends using a cut-off of 2.6 mmol/L in at risk infants*, as blood glucose levels below this are associated with adverse outcomes, especially if persistent or repeated.
After two hours of age, if the infant is well and is not at risk for neonatal hypoglycaemia, routine care should be given, including feeding on demand.
The infant should not be tested unless they become unwell.
In infants who are at risk for neonatal hypoglycaemia (SGA, LGA,
IUGR, preterm, or infant of a diabetic mother), blood glucose levels should be checked at two hours of age, after at least one effective feed, and then every 3-6 hours after that, before feeds, provided that the infant remains well and glucose levels are stable.*
*For detailed information on screening, dx, and rx please see:
- Glucose Monitoring of the Healthy Newborn, 0 to 36 hours of age This is the flow chart from the Children Hospital of Philadelphia and has additional topic resource links on the page.
- Postnatal Glucose Homeostasis in Late-Preterm and Term Infants [PubMed Abstract] [Full Text HTML] [Full Text PDF]. Pediatrics. 2011 Mar;127(3):575-9.