[Incidence of typical nephrocalcinosis ultrasound findings in premature infants during enteral calcium and phosphate administration].
Supplementation of calcium and phosphate is recommended in nutrition of low birth weight infants to ensure a physiological development of postnatal bone mineralisation. To investigate whether high dose calcium supplementation increases the risk of renal calcification in preterm infants, serial ultrasound examinations were performed in 30 preterm infants (gestational age 29.5 (26-35) weeks; birth weight 1382 (610-2010) g) before, during and after oral calcium and phosphate supplementation. Total calcium input was on average 3.1 mmol/kg/d, total phosphate input on average 2.1 mmol/kg/d). All children showed normal kidney ultrasound before entering the study. During mineral supplementation three children developed hyperechoic renal medullary pyramids, the typical ultrasound pattern of nephrocalcinosis. Supplementation was stopped immediately and pathologic ultrasound patterns disappeared in all 3 children.