Neonatal hypocalcemia

Neonatal hypocalcemia is an abnormal clinical and laboratory hypocalcemia condition that is frequently observed in infants. It is commonly presented within the first 72 hours of a newborn's life.^[1] Neonatal hypocalcemia can cause seizures in infants requiring a calcium infusion until homeostasis is achieved; allowing for positive clinical outcomes within weeks of treatment.^[2][3][4][5]

Neonatal hypocalcemia
Specialty	Neonatology

Healthy term infants go through a physiological nadir of serum calcium levels at 7.5 - 8.5 mg/dL by day 2 of life. Hypocalcemia is a low blood calcium level. A total serum calcium of less than 8 mg/dL (2mmol/L) or ionized calcium less than 1.2 mmol/L in term neonates is defined as hypocalcemia. In preterm infants, it is defined as less than 7mg/dL (1.75 mmol/L) total serum calcium or less than 4mg/dL (1 mmol/L) ionized calcium.

Both early onset hypocalcemia (presents within 72h of birth) and late onset hypocalcemia (presents in 3-7 days after birth) require calcium supplementation treatment.

Infants with intrauterine growth retardation, perinatal asphyxia, preterm, and diabetic mothers are most likely to develop neonatal hypocalcemia.^[1] It is not understood why premature infants have hypocalcemia, but a proposed idea is that a large increase of calcitonin may lead to hypocalcemia. Another hypothesis includes impaired secretion of parathyroid hormone.^[6]

Cause

Risk factors of early neonatal hypocalcemia

• Prematurity
• Perinatal asphyxia
• Diabetes mellitus in the mother
• Maternal hyperparathyroidism
• Intrauterine growth retardation (IUGR)
• Iatrogenic

Risk factors

Risk factors of late neonatal hypocalcemia

• Exogenous phosphate load
• Use of gentamicin
• Gender and ethnic: late neonatal hypocalcemia occurred more often in male infants and Hispanic infants
• Others

• Magnesium deficiency
• Vitamin D deficiency ^[7][2]
• Transient hypoparathyroidism of newborn
• Hypoparathyroidism due to other causes (DiGeorge Syndrome)