In healthy term babies, calcium concentrations decrease for the first 24-48 hours and thereafter progressively rise to the mean values as in older children and adults.

Hypocalcemia is defined as total serum calcium concentrations below 7 mg/dl and ionized calcium less than 4 mg/dl. Most infants do not become symptomatic till calcium levels are below 6 mg/dl.

High risk infants :

• Preterm babies
• Infants of diabetic mother
• Birth asphyxia
• Sepsis
• Respiratory distress
• Infants with functional or transient hypoparathyroidism
• Small for gestation age infants

Diagnosis :

Hypocalcemia may present as "early onset hypocalcemia" ( during the 1st 3 days ) - usually in stressed and preterm infants. It is usually mild or asymptomatic. Hypocalcemia can also occur at the end of the 1st week called "late onset hypocalcemia", seen usually in hypoparathyroidism. It usually presents with seizures, tetany, irritability, tremors, jitteriness and lethargy.

Hence, it is often necessary to screen high risk infants. Preterm infants and stressed infants are usually monitored for calcium levels at 12, 24 and 48 hours of life and when indicated. Serum magnesium levels should also be done as hypocalcemia can result in intractable hypocalcemia.

Treatment :

Calcium gluconate (10% solution) is given IV at 1-2 ml/kg (100 mg/kg) slowly to treat symptomatic hypocalcemia. IV calcium should be given slowly as rapid infusion can cause sudden elevation of serum calcium level causing bradyarrythmias. Also care should be taken to prevent subcutaneous extravasation as it may cause severe necrosis and subcutaneous calcifications. Maintenance therapy is given at 200 mg/kg/day IV and increased as needed to maintain serum calcium level at 7 to 8 mg/dl.

Therapy should be then initiated for specific cause of hypocalcemia. Intractable hypocalcemia due to hypomagnesemia is treated with magnesium sulphate (0.2ml/kg of 50 % solution or 0.4 ml/kg of 25% solution) intramuscularly or intravenously. Hypocalcemia associated with hyperphosphatemia is treated by giving the infants a low phosphorous formula or human milk and adding calcium supplements to the milk. Infants with vitamin D deficiency are treated with oral Vitamin D analogues (dihydrotachysterol and calcitriol ).

Also See "Frequently Asked Questions On Hypocalcemia"

Last created on 15-12-2000
Last updated on 01-07-2006