Hypoglycemia in the preemie and neonatal population is defined as a blood glucose level less than 50 mg/dL. Glucose (AKA sugar) is the main source of fuel for the brain and body and is one of the most essential nutrients that they NEED in order to function. Hypoglycemia is the most common metabolic disturbance occurring in the neonatal period. Healthy infants experience an expected drop in blood glucose concentrations immediately following birth as a part of the normal physiologic transition to extrauterine life. Preterm, intrauterine growth restricted and small for gestational age infants, however, are at risk for hypoglycemia because they are born with decreased glycogen stores, decreased adipose tissue, and experience increased metabolic demands due to their rapidly growing and developing brains.
Which newborns are at risk for hypoglycemia?
Babies are more likely to have hypoglycemia include:
Babies born to mothers with diabetes
Babies who are small for gestational age or growth-restricted
Preterm babies, especially those with low birth weights
Babies born under significant stress
Babies with mothers treated with certain medicines such as steroids
Babies who are large for their gestational age
Infants of diabetic mothers (IDM) and large for gestational age (LGA) infants experience fetal hyperinsulinism, putting them at risk for hypoglycemia in the immediate postnatal period. The placenta supplies the fetus with a direct source of glucose to maintain fetal glucose concentrations proportional to maternal levels. Prolonged elevations in maternal glucose concentrations result in pancreatic overstimulation and overproduction of insulin. Why does this happen? After birth, babies are no longer supplied with the high sugars levels provided by the mother (they are “cut off” from their dealer). However, the baby continues to overproduce insulin without actually needing it. This high insulin results in a significant drop in the newborn's blood glucose level. This can become very dangerous and toxic to the baby, and if the level drops critically low, this can lead to severe brain damage.
Clinical manifestations of hypoglycemia can include but are not limited to:
Apnea/bradycardia
Lethargy & fatigue
Jitteriness/shakiness
Color change, pale skin, mottling
Hypothermia
Floppy muscles/poor muscle tone
Disinterest in feeding
Seizures [in severe cases]
How is Hypoglycemia treated?
Treatment will depend on your baby's gestational age and overall health. If your baby eats by mouth, feeding him/her a bottle of formula, breast milk or glucose & water may resolve the problem. If your baby is unable to feed, administer a bolus of D10W via an IV. Additional tests and labs may be required if the issue does not resolve shortly after.