All issues > Volume 17(2); 1974

Original Article

J Korean Pediatr Soc. 1974;17(2):103-110. Published online February 28, 1974.

Serum Calcium and Phosphorus in Premaiure and Full-Term Infants

Jae Jung Choi¹

¹Department of Pediatrics, College of medicine; Busan National University

Abstract

Neonatal hypocalcemia occurs in full-term infants, and more frequently； in premature infants. Various etiologic factors for hypocalcemia of new-born infants have been proposed in the litera- tures: parathyroid1 insufficiency or functionally imature parathyroid, serum phosphorus levels,, fasting and various diets, rate* of growth and vitamin- D deficiency. There was large literature on the sa-called normal serum calcium level in newborn infant, but less was known in newborn infant in our country. Thus, author attempts to evaluate blood serum levels of calcium and inorganic phosphorus in premature versus full-term infants, before and after first feeding, correlation between serum calcium and inorganic phosphorus, and changes of blood serum levels of calcium and phosphorus according to age, but the etiology of neonatal hypocalcemia was not elucidated by this study. The blood serum levels of calcium and inorganic phosphorsu were determined repeatedly in 14 premature and 10 full-term infants durine first three weeks of. life, and the results are obtained as following: 1. Serum calcium levels were lower in premature infants, with a mean value of 8.77土0.86mg% versus 9.34±1.03 mg% for full-term infanta serum inorganic phosphorus levels were higher in. premature infants, with a. mean value of 7.38±1.27 mg.% versus 6.32士0. 26 mg% for full-term infants. In the levels of calcium and - phosphorus there were significant differences between premature and full-term infants respectively, which suggested that risk of hypocalcemia was greaterin prem- ature infants. 2. 14.2% of premature infants had serum calcium levels below 8mg%，but none of full-term infants had. 23.1% of premature infants had serum inorganic phosphorus levels above 8mg% versus 11.1% for full-term infants. 3. Serum calcium levels were lower before first feeding, with a mean value of 8.50±0.88mg% versus 9.22±0.82mg% after firstfeeding. 4. There was no significant correlation between serum calcium and inorganic phosphorus. 5. Lower serum calcium value and higher serum inorganic phosphorus value were found in the first and fourth to seventh days of life, which suggested that the neonatal hypocalcemia tends to occur in these periods of early life.

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