All issues > Volume 41(3); 1998

Original Article

J Korean Pediatr Soc. 1998;41(3):378-382. Published online March 15, 1998.

Random Urine Ca/Cr Ratio in Healthy Neonates

Hea Young HY Lee¹, So Young SY Park¹, Eun Sun ES Yoo¹, Eun Ae EA Park¹, Seung Joo SJ Lee¹

¹Department of Pediatrics, College of Medicine, Ewha Womans University, Seoul, Korea

Correspondence Hea Young HY Lee ,Email: 1

Abstract

Purpose
: Recently, in high risk preterm infants, we experienced high incidence of hypercalciuria, nephrolithiasis & nephrocalcinosis. To screen hypercalciuria, we need the normal value of random urine Ca/Cr ratio in healthy neonates according to gestational age, postnatal age, milk and calcium intake.
Methods
: Random urine Ca/Cr ratio was checked in 260 healthy full-term infants at the 2-7th day, and in 40 preterm infants at the 3-16th day when they started formula feeding at Ewha Universaity Mok-dong Hospital from March 1995 to October 1995. We calculated calcium amount in formulas and we excluded the neonates who needed extra calcium supplement.
Results
: There were no significant relationships between random urine Ca/Cr ratio and body weight or gestational age. There were significant logistic positive relationships between random urine Ca/Cr ratio and postnatal age(r=0.47, P < 0.05) or calcium intake(r=0.52, P < 0.05). The velocity of increase in random urine Ca/Cr ratio in term and preterm infants is not significantly different. The normal values of random urine Ca/Cr ratio in healthy term and preterm infants were 0.026¡¾0.013(Max. 0.052) at the early neonatal period with low calcium intake, and 0.075¡¾0.0310 (Max. 0.137) at the late neonatal period with adequate calcium intake.
Conclusion
: Random urine Ca/Cr ratio was very low in healthy neonates and increase in a logistic line according to calcium(milk) intake. New normal value of random urine Ca/Cr ratio in neonates according to calcium(milk) intake is suggested to screen hypercalciuria.

Keywords :Random urine Ca/Cr ratio, Neonate, Calcium intake