All issues > Volume 30(6); 1987

Original Article

J Korean Pediatr Soc. 1987;30(6):613-624. Published online June 30, 1987.

A Study on Serum Ca, P, Mg, Parathyroid Hormone, Calcitionin, and 1, 25-dihydroxyvitamin D Concentrations in Normal Newborn and Low Birth Weight Infants.

In Bock Lee¹, Chang Soo Ra¹

¹Department of Pediatrics, College of Medicine, Chosun University

Abstract

Early neonatal hypocalcemia occurs within the first few days of life, with the lowest concentrations of serum calcium being reached at 24 to 48 hours of age. An infant can be considered to be hypocalcemic when serum calcium concentrations are below 7 mg/dl or when ionized calcium concentrations are below 3 to 3.5 mg/dl. The most commonly encountered causes of neonatal hypocalcemia are prematurity, birth asphyxia, and infants of mothers with diabetes. Early neonatal hypocalcemia appears to be related to decreased calcium intake in associated with temporaly neonatal hypoparathyroidism, possible hypercalcitonemia, and in some instances, possible disorders vitamin D metabolism. To investigate the influence of parathyroid hormone, calcitonin, and 1,25-dihydroxyvitamin D for calcium concentrations in the newborn infants, authors studied serum calcium, phosphorus, magnesium, parathyroid hormone, calcitonin, and 1,2 5-dihy dr oxy vitamin D concentrations in 20 cases of normal newborn infants and their mothers at delivery, and in 9 cases of normal newborn infants and in 7 cases of low birth weight infants during the first five days of life. The following results were obtained: 1) The mean serum calcium levels of cord blood in 20 cases of normal newborn infants were 10.46 ±0.88 mg/dl and those of maternal blood in 20 cases of the mothers were 9.21 ±0.85 mg/dl. In comparison of serum calcium levels for the normal newborn and the mother, the serum calcium levels of the newborn infants were significantly higher than those of mothers(p < 0.005). 2) The mean serum phosphorus levels of cord blood in 20 cases of normal newborn infants were 6.08±1.67 mg/dl and those of maternal blood in 20 cases of the mothers were 4.56±1.89 mg/dl. In comparison of serum phosphorus levels for the normal newborn and the mothers, the serum phosphorus levels of the newborn infants were significantly higher than those of the mothers(p < 0.005). 3) The mean serum magnesium levels of cord blood in 20 cases of normal newborn infants were 2.01 ±0.45 mg/dl and those of maternal blood in 20 cases of the mothers were l,67±0.19 mg/dl. Incomparison of serum magnesium levels for the newborn and the mother, the serum magnesium levels of the newborn infants were significantly higher than those of the mothers(p < 0.005). 4) The mean serum parathyroid hormone levels of cord blood in 20 cases of normal newborn infants were 56.1 ±65.0 pg/ml and those of maternal blood in 20 cases of the mothers were 104.5± 146.8 pg/ml. In comparison of serum parathyroid hormone levels for the normal newborn and the mothers, the serum parathyroid hormone levels of the normal newborn infants were significantly lower, than those of the mothers(p<0,01). 5) The mean serum calcitonin levels of cord blood in 20 cases of normal newborn infants were 60.6±44.2 pg/ml and those of maternal blood in 20 cases of the mothers were 28.1 ±27.1 pg/ml. In comparison of serum calcitonin levels for the normal newborn and the mother, the serum calcitonin levels of the normal newborn infants were significantly higher than those of the mothers(p<0.01). 6) The mean serum 1,25-dihydroxyvitamin D levels of cord blood in 20 cases of normal newborn infants were 28.6±13.6 pg/ml and those of maternal blood in 20 cases of the mothers were 42.1 ±3.0. In comparison of serum 1,25-dihydroxyvitamin D levels for the normal newborm and the mothers, the serum 1,25-dihydroxyvitamin D levels of the newborn infants were lower than those of the mothers, however, statistically not significant(p > 0.2). 7) The mean serum calcium levels in 9 cases of normal newborn infants at the first, third and fifth days of life were 9.28±1.26 mg/dl, 8.68±1.09 mg/dl, and 9.07±1.14 mg/dl respectively, and the those in 7 cases of low birth weight infants were 7.67 ±1.84 mg/dl, 8.71 ±1.11 mg/dl, and 8.50 ±0.87 mg/dl respectively. 8) The mean serum parathyroid hormone levels in 9 cases of normal newborn infants at the first, third and fifth days of life were 84.6±48.5 pg/ml, 88.3±52.7 pg/ml, and 161.1 ±140.4 pg/ml respectively, and those in 7 cases of low birth weight infants were 57.8±23.1 pg/ml, 68.5±55.0 pg/ml, and 121.1 ± 106.8 pg/ml respectively. 9) The mean serum calcitonin levels in 9 cases of normal newborn infants at the first, third and fifth days of life were 69.9±52.2 pg/ml, 71.6±52.7 pg/ml, and 86.6±68.3 pg/ml respectively, and those in 7 cases of low birth weight infants were 61.8±49.6 pg/ml, 83,0±53.4 pg/ml, and 86.6±68.3 pg/ml respectively. 10) The mean serum 1,25-dihydroxyvitamin D levels in 9 cases of normal newborn infants at the first, third and fifth days of life were 46.0 ±19.3 pg/ml, 33.2 ±17.3 pg/ml, and 49.0 ±33.9 pg/ml respec- tively, and those in 7 cases of low birth weight infants were 29.6±8.2 pg/ml, 46.2±19.3 pg/ml, and 47.2±15.2 pg/ml respectively.

Keywords :Serum Ca; P; Mg; PTH; Calcitonin; 1,25-dihydroxyvitamin D levels; newborn infants; Low birth weght infants.