Abstract Serial magnesium determinations by atomic absorption spectrophotometry were performed in the first five days of age on the serum of 91 infants with birth weights less than 2.0 kg (4.4 lb). There was a gradual rise in Mg levels with postnatal age, in both preterm infants with birth weights appropriate for gestational age and infants who were small for gestational age. Decreased Mg levels were observed in infants who were small for gestational age, and in infants born of toxemic mothers and primiparous mothers. There was an inverse relation between Mg levels and gestational age. There was no significant correlation between Mg levels and serum calcium, phosphorus, or protein levels. The mean of all determinations was 2.26 mg/100 ml ± SD 0.34. These figures are similar to adult values. Three infants with serum Mg values below 2 SD from the mean exhibited signs of increased neuromuscular irritability. The low Mg levels reverted to normal without treatment. References 1. Mays JE, Keele DK: Serum magnesium levels in healthy children and various disease states . Amer J Dis Child 102:623-624, 1961. 2. Bajpai PC, Sugden D, Ramos A, et al: Serum magnesium levels in the newborn and older child . Arch Dis Child 41:424-427, 1966.Crossref 3. Anast CS: Serum magnesium levels in the newborn . Pediatrics 33:969-974, 1964. 4. Paunier L, Radde IC, Kooh SW, et al: Primary hypomagnesemia with secondary hypocalcemia in an infant . Pediatrics 41:385-402, 1968. 5. Davis JA, Harvey DR, Yu JS: Neonatal fits associated with hypomagnesemia . Arch Dis Child 40:286-290, 1965.Crossref 6. Dooling EC, Stern L: Hypomagnesemia with convulsions in a newborn infant . Canad Med Assoc J 97:827-831, 1967. 7. Bottini E, Ventura G, Cocciante G, et al: Serum magnesium in icteric newborn undergoing exchange-transfusion . Biol Neonat 12:102-106, 1968.Crossref 8. Lipsitz PJ, English IC: Hypermagnesemia in the newborn infant . Pediatrics 40:856-863, 1967. 9. MacDonald MA, Watson L: The determination of magnesium in biological materials by atomic absorption spectrophotometry . Clin Chim Acta 14:233-241, 1966.Crossref 10. Sunderman FW Jr, Carroll JE: Measurements of serum calcium and magnesium by atomic absorption spectrometry . Amer J Clin Path 43:302-310, 1965. 11. Fiske CH, Subbarow Y: The colorimetric determination of phosphate . J Biol Chem 66:375-400, 1925. 12. Natelson S: Microtechniques of Clinical Chemistry , ed 2. Springfield, Ill, Charles C Thomas Publisher, 1963, pp 346-349. 13. Snedecor GW: Statistical Methods , ed 4. Ames, Iowa, Iowa State College Press, 1948, pp 54-74, 138-168, 318-339. 14. Lubchenco LO, Hansman C, Dressler M, et al: Intrauterine growth as estimated from live-born birth weight data at 24 to 42 weeks of gestation . Pediatrics 32:793-800, 1963. 15. Stewart WF, Hutchinson F, Fleming LW: The estimation of magnesium in serum and urine by atomic absorption spectrophotometry . J Lab Clin Med 61:858-872, 1963. 16. Alcock N, MacIntyre, I, Radde I: Determination of magnesium in biological fluids and tissues by flame spectrophotometry . J Clin Path 13:506-510, 1960.Crossref 17. Gittleman IF, Pinkus JB, Schmertzler E: Interrelationship of calcium and magnesium in the mature neonate . Amer J Dis Child 70:119-124, 1964. 18. Orange M, Rhein HC: Microestimation of magnesium in body fluids . J Biol Chem 189:379-386, 1951. 19. Briscoe AM, Ragan C: Relation of magnesium to calcium in human blood serum . Nature 214:1126-1127, 1967.Crossref 20. Pruden EL, Meier R, Plaut D: Comparison of serum magnesium values by photometric, fluorometric, atomic absorption and flame emission methods . Clin Chem 12:613-619, 1966. 21. Wacker WEC, Zida C, Fuwa K: Accuracy of determination of serum Mg by flame emission and atomic absorption spectrophotometry . Nature 202: 659-661, 1964.Crossref 22. Wacker WEC, Parrisi AF: Magnesium metabolism . New Eng J Med 278:658-661, 712-717, 1968.Crossref 23. Tsang RC, Oh W: Neonatal hypocalcemia in low birth weight infants. Pediatrics, to be published. 24. Bakwin H: Pathogenesis of tetany of the newborn . Amer J Dis Child 54:1211-1226, 1937. 25. MacIntyre I, Boss S, Troughton VA: Parathyroid hormone and magnesium homeostasis . Nature 198:1058-1060, 1963.Crossref 26. Tibbets DM, Aub JC: Magnesium metabolism in health and disease: II. The effect of the parathyroid hormone . J Clin Invest 16:503-509, 1937.Crossref 27. Gardner LI, MacLachlan EA, Pick W, et al: Etiologic factors in tetany of newborn . Pediatrics 5:228-240, 1950. 28. Wigglesworth JS: Foetal growth retardation . Brit Med Bull 22:13-15, 1965. 29. Aikawa JK, Bruns PD: Placental transfer and fetal tissue uptake of Mg28 in the rabbit . Proc Soc Exp Biol Med 105:95-98, 1960.Crossref 30. Scott KE, Usher R: Fetal malnutrition: Its incidence, causes and effects . Amer J Obstet Gynec 94:951-963, 1966.
American Journal of Diseases of Children – American Medical Association
Published: Jul 1, 1970