Many newborns show a drop in serum calcium within a few days of birth. The risk may be even greater if there are maternal and/or neonatal disorders. The condition is related to a number of factors, including a transient physiologic hypoparathyroidism and increased release of thyrocalcitonin.


Risk factors:

(1) maternal diabetes

(2) maternal hyperparathyroidism

(3) maternal vitamin D deficiency

(4) prematurity

(5) intrauterine growth retardation

(6) prolonged delivery, anoxia and/or asphyxia

(7) familial hypoparathyroidism


Clinical manifestations:

(1) onset during the first 72 hours after birth

(2) convulsions

(3) ECG changes (prolonged QT interval, conduction abnormalities)

(4) tetany

(5) transient course


Laboratory testing:

(1) low serum calcium. The ionized serum calcium may be more reliable indicator than the total serum calcium.

(2) low serum parathyroid hormone (PTH) levels

(3) The infant should be screened for hypomagnesemia, especially if the hypocalcemia does not respond as expected to conventional therapy.


Differential diagnosis:

(1) rickets of prematurity (see Chapter 20)


To read more or access our algorithms and calculators, please log in or register.