STUDY OF THE URINARY CALCIUM CREATININE R ATIO IN INFANTS, PRETERM AND TERM NEWBORNS

Urinary calcium/creatinine ratio (U Ca/creat) was studied in infants, term and preterm newborn babies. In 31 1,5-24 months old healthy infan ts, the median U Ca/creat was 0,16 mmol/mmol (range 0,013-1,17) and wa s similar to the value obtained in children older than 4 years. In 55 healthy full-term newborns studied in the first week of life, the medi an U Ca/creat was 0,12 mmol/mmol. However the range of values was extr emely wide (0,0006-4,75), suggesting that the U Ca/creat ratio is of l ittle interest to screen for hypercalciuria during the neonatal period . In 31 premature newborns, the median U Ca/creat was 1,08 mmol/mmol, a value significantly higher than in the two other groups (P < 0,001); as in the term newborns there was a very wide range of values (0,057- 6,83). However after excluding the premature babies with elevated seru m 25 OHD level, this difference was not statistically significant.