Hypercalciuria, defined as an increased urinary calcium:creatinine ratio, was noted in those developing nephrocalcinosis.[2,6,26,28] Premature infants with nephrocalcinosis compared with those without nephrocalcinosis had a significantly higher urinary calcium:creatinine ratio at 2 weeks, 4 weeks, from 2 to 6 weeks of life, at term, and at study age (4.7 ± 1.1 years). Differences in urinary calcium:creatinine ratio reported between infants with and without nephrocalcinosis did not persist over time in some studies.[4,16] Higher urinary calcium:creatinine ratio noted in infants with nephrocalcinosis in some studies was not found in other studies reporting findings at various ages.[3,17,27,29] Since both premature infants with and without nephrocalcinosis have calcium:creatinine ratios indicative of hypercalciuria, or abnormal calcium load test, it has been inferred that prematurity is a risk factor for nephrocalcinosis;[16,26,29] however, those without nephrocalcinosis demonstrate improvement while those who develop nephrocalcinosis show an increase in renal calcium excretion. One can surmise that preterm infants may have a natural tendency for hypercalciuria, or alternatively, hypercalciuria may be an adverse consequence of nephrocalcinosis.
Pediatr Health. 2010;4(1):24-35. © 2010 Future Medicine Ltd.
Cite this: Should We Screen Preterm Infants for Nephrocalcinosis? An Evidence-based Decision - Medscape - Feb 01, 2010.