Medical expert of the article
New publications
Hypocalcemia in newborns
Last reviewed: 04.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Hypocalcemia is a total serum calcium concentration of less than 8 mg/dL (less than 2 mmol/L) in term infants and less than 7 mg/dL (less than 1.75 mmol/L) in preterm infants. It is also defined as an ionized calcium level of less than 3.0 to 4.4 mg/dL (less than 0.75 to 1.10 mmol/L) depending on the method (electrode type) used. Manifestations include hypotension, apnea, and tetany. Treatment of hypocalcemia is with intravenous or oral calcium.
[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ], [ 8 ], [ 9 ], [ 10 ], [ 11 ]
What causes hypocalcemia?
Neonatal hypocalcemia may be early (within the first 2 days of life) or late (more than 3 days); late-onset hypocalcemia is rare. Some infants with congenital hypoparathyroidism [eg, DiGeorge syndrome with parathyroid agenesis or dysgenesis] have both early and late (protracted) hypocalcemia.
Risk factors for early hypocalcemia include prematurity, small birth weight, maternal diabetes, and intrapartum asphyxia. Mechanisms vary. Normally, parathyroid hormone helps maintain normal calcium levels when the continuous supply of ionized calcium across the placenta ceases at birth. Transient, relative hypoparathyroidism may cause hypocalcemia in premature and some small-for-gestational-age infants whose parathyroid glands are not yet functioning adequately; and in infants of diabetic or hyperparathyroid mothers because these women have higher than normal ionized calcium levels during pregnancy. Intrapartum asphyxia may also increase levels of calcitonin, which inhibits calcium release from bone, leading to hypocalcemia. Other infants lack the normal renal response to parathyroid hormone, resulting in phosphaturia; Elevated phosphate levels (P04) lead to hypocalcemia.
Symptoms of hypocalcemia
Symptoms of hypocalcemia rarely occur unless total calcium falls below 7 mg/dL (less than 1.75 mmol/L) or ionized calcium falls below 3.0 mg/dL. Manifestations include hypotension, tachycardia, tachypnea, apnea, difficulty feeding, agitation, tetany, and seizures. Similar symptoms may occur with hypoglycemia and withdrawal.
Diagnosis of hypocalcemia
The diagnosis is based on the degree of decrease in total or ionized calcium in the serum; ionized calcium is a more physiological indicator because it excludes the influence of protein level and pH. Prolongation of the corrected QT interval (QT.) on the ECG also indicates hypocalcemia.
Treatment of hypocalcemia
Early-onset hypocalcemia usually resolves within a few days, and neonates with calcium levels greater than 7 mg/dL (greater than 1.75 mmol/L) or ionized calcium greater than 3.5 mg/dL who have no clinical signs of hypocalcemia rarely require treatment. Term infants with calcium levels less than 7 mg/dL (less than 1.75 mmol/L) and premature infants with calcium levels less than 6 mg/dL (less than 1.5 mmol/L) should be treated with 2 mL/kg (200 mg/kg) of 10% calcium gluconate given slowly intravenously over 30 minutes. Too rapid an infusion may cause bradycardia, so heart rate should be monitored during the infusion. Careful observation of the intravenous injection site is also necessary, since tissue infiltration by the calcium solution is irritating and may cause local tissue injury or necrosis.
After emergency correction of hypocalcemia, calcium gluconate can be administered long-term along with other intravenous solutions. Starting with 400 mg/(kg/day) of calcium gluconate, the dose can be gradually increased to 800 mg/(kg/day) if necessary to prevent recurrence of hypocalcemia. When the child begins to be fed orally, the formula can be enriched with the same daily dose of calcium gluconate by adding 10% calcium gluconate solution to the formula. Additional calcium administration is usually necessary for several days.
If hypocalcemia has a late onset, calcitriol or extra calcium may need to be added to the infant's formula to provide a Ca:PO44:1 ratio until normal calcium levels are maintained. Oral calcium preparations contain large amounts of sucrose, which may cause diarrhea in premature infants.