Study of the offspring from parathyroidectomized and hypercalcaemic rats showed that both high and low levels of maternal plasma calcium produced abnormalities in the offspring. Both groups of offspring had hypocalcaemia at birth which reverted to normal by the 7th day of life. All the offspring grew poorly compared with controls. The growth defect in the offspring of the hypocalcaemic rats was reversed if the offspring were reared by normal rats, and in the offspring of the hypercalcaemic rats was accompanied by abnormalities of the fur, including focal alopecia, which reverted to normal when the offspring were weaned on to a normal diet. The calcium concentration in the milk of the hypercalcaemic rats was higher than that in the milk of normal and parathyroidectomized rats.
In the rat the plasma and milk calcium levels in the mother appeared to be important in the aetiology of neonatal hypocalcaemia and growth. It is suggested that the estimation of the plasma calcium in the mother should become a routine procedure in the investigation of cases of neonatal tetany in infants.