Plasma Calcium and Magnesium in Newborn Babies

Abstract

. (1970). Archives of Disease in Childhood, 45, 506. Plasma calcium and magnesium in newborn babies. Normal values for plasma calcium and magnesium levels during the first week of life, in breast-and bottle-fed babies, have been determined. It has been shown on the sixth day that plasma levels of calcium, magnesium, and protein are all significantly lower in bottle-fed babies than in breast-fed babies, while the reverse is true of the plasma inorganic phosphorus.The normal babies have been compared with 30 babies who had convulsions, beginning towards the end of the first week of life. In only six of the babies was the plasma calcium outside our normal range and only four had abnormally low magnesium levels. As so many of these babies had calcium and magnesium levels within the normal range it must seriously be questioned whether hypocalcaemia or hypomagnesaemia could have been the sole cause of the convulsions.In order to establish normal values for the first week of life, calcium and magnesium have been measured in samples of plasma for normal infants who were either breast-or bottle-fed.Convulsions beginning on the 5th to 8th days of life are often attributed to hypocalcaemia (Bakwin, 1937) or hypomagnesaemia (Davis, Harvey, and Yu, 1965). A group of babies with convulsions at the end of the first week has been compared with the normal infants.Material and Methods Two maternity units were used for this survey. The first series was conducted at Hammersmith Hospital from June to September 1967; the blood was collected immediately before the 9 a.m. feed from normal babies on the first seven days of life. Samples obtained from 85 babies were not consecutive though most babies were bled more than once. Heel-prick samples were obtained without squeezing and were centrifuged and separated immediately; any grossly haemolysed samples were discarded. Heparin was used as an anticoagulant. The babies' weights ranged from 2300 to 4460 g., and their gestational ages from 38 to 42 weeks. They were either entirely breast fed, apart from an initial feed of glucose and water, or were fed on an evaporated milk formula ('Carnation Milk'). This was diluted 1 part with 21 parts of water, and given in volumes of 90-160 ml./kg. per 24 hours on the second day, increasing gradually to 140-160 ml./kg. per 24 hours on the sixth day. In this dilution the milk contained: phosphorus 67 mg./100 ml.; calcium 76 mg./100 ml., and vitamin D 28 I.U./100 ml.

Association of Oedema and Hypomagnesaemia with Hypocalcaemic Tetany of the Newborn

“…The low serum sodium levels are in keeping with dilution in the intravascular compartment. It is more likely that the oedema is caused by salt and water retention when the Though the changes which occur in serum calcium and magnesium levels in the neonatal period have been studied by others (Gittleman et al, 1964;Harvey et al, 1970), there is little agreement on the precise values which should be accepted as abnormal. A serum calcium level of 7 mg/100 ml or below was chosen in this paper, and this is lower than has generally been accepted in the past (Keen, 1969).…”

Post-halothane Jaundice in Relation to Previous Administration of Halothane

“…No attempt has been made to define accurately normal serum magnesium levels. Harvey et al (1970), using atomic absorption spectrophotometry, showed a mean serum magnesium concentration of 1-4 mg/100 ml in 25 bottle-fed babies on the sixth day of life. However, the range of results was very wide, 0-85-1 9 mg/100 ml.…”

“…Though the changes which occur in serum calcium and magnesium levels in the neonatal period have been studied by others (Gittleman et al, 1964;Harvey et al, 1970), there is little agreement on the precise values which should be accepted as abnormal. A serum calcium level of 7 mg/100 ml or below was chosen in this paper, and this is lower than has generally been accepted in the past (Keen, 1969).…”

A Study of Serum Calcium Levels during First Week of Life in Normal Term Neonates

“…Before birth, the foetus has a constant supply of water and electrolytes from the mother across the placenta; foetal water and electrolyte homeostasis is largely a function of placental and maternal homeostatic mechanisms that is reflected in cord blood. 2 After birth neonate must rapidly assume responsibility for its own fluid and electrolyte homeostasis in an environment in which fluid and electrolyte availability and losses fluctuate much more widely than in utero. Moreover, for reasons that are not understood, the transition from foetal to neonatal life is associated with what have come to be accepted as normal changes in fluid and electrolyte balance.…”

“…These small changes in fluid and electrolyte quantity represent large proportionate changes in neonate because of neonate's small size. 1,2 The reference ranges of serum Calcium is usually established on the basis of the statistical distribution of results within a sample of population. 1 The studies done to find normal distribution levels of these electrolytes till date are very limited.…”