Babies need sugar (glucose) for energy. Most of that glucose is used by the brain.

The developing baby gets glucose from the mother through the placenta. After birth, the baby gets glucose by producing it in the liver and from food.

Glucose levels can drop if:

• There is too much of the hormone, insulin (hyperinsulinism). Insulin pulls glucose from the blood into the cells to be used for energy.
• There is not enough glycogen, the form in which glucose is stored in the body.
• The baby is not producing enough glucose.
• The baby's body is using more glucose than is being produced.

Neonatal hypoglycemia occurs when the newborn's glucose level is:

• Less than 30 mg/dL in the first 24 hours of life
• Less than 45 mg/dL after the first 24 hours of life

Hypoglycemia is the most common metabolic problem in newborns. It occurs in approximately 1 - 3 out of every 1,000 births.

Infants with the following risk factors are at high risk for neonatal hypoglycemia:

• Blood infection (sepsis)
• Endocrine disorders, such as low thyroid hormone production (hypothyroidism)
• Inborn errors of metabolism
• Intrauterine growth restriction
• Lack of oxygen shortly after birth
• Large for gestational age
• Mother with diabetes
• Mother who may have chorioamnionitis or an infection around the time of the baby's birth
• Premature birth
• Small for gestational age

Infants with hypoglycemia may not have symptoms. If they do occur, symptoms may include:

• Bluish-colored skin (cyanosis)
• Breathing problems
• Decreased muscle tone (hypotonia )
• Grunting
• Irritability
• Listlessness
• Nausea, vomiting
• Pale skin
• Pauses in breathing (apnea)
• Poor feeding
• Rapid breathing
• Problems with maintaining body heat
• Shakiness
• Sweating
• Tremors
• Seizures

Newborns at risk for hypoglycemia should have a blood test to measure blood sugar levels every few hours after birth. The health care provider should continue taking blood tests until the baby's blood sugar level is normal.

Other possible tests:

• Newborn screening for metabolic disorders
• Urine tests

Infants with hypoglycemia may need to receive:

• Feeding with breast milk or formula within the first few hours after birth, either by mouth or through a tube inserted through the nose into the stomach (nasogastric gavage)
• Feeding with a sugar solution through a vein (intravenously) or by mouth (orally)

Treatment normally continues for a few days to 1 week.

If the low blood sugar continues, the baby may also receive medication to increase blood glucose levels (diazoxide) or to reduce insulin production (ocreotide).

In rare cases, newborns with very severe hypoglycemia who don't improve with treatment may need surgery to remove part of the pancreas (to reduce insulin production).