Calcium, magnesium and phosphorus in foetal tissues

Abstract

Ca, Mg and P were determined in the serum skeletal muscle, membranes and fluids of the rabbit at 21 days'' gestation, of the pig at 19 and 46 days, and of the human fetus at several stages of gestation. In the fetal muscles the concentrations of Ca were higher, and of Mg and P lower, than in those of adults. The Ca was probably intracellular. Fetal serum may contain more Ca, Mg and inorganic P per unit volume than the maternal serum. The amniotic membranes and the allantoic fluids may contain high concentrations of Ca. When there was much Ca in the allantoic fluid of the pig it was accompanied and probably maintained in solution by high concentrations of citrates.