[Neonatal hyperparathyroidism secondary to maternal hypoparathyroidism (author's transl)].

Three cases of neonatal hyperparathyroidism are reported: 2 children born to a mother with idiopathic hypoparathyroidism and a boy born to a mother with pseudohypoparathyroidism. Severe demineralization, decreased plasma calcium levels and very low phosphorus levels were seen in all three cases. The PTH level was high in the two cases in which is was measured. In the second of these, the lack of vitamin D administration since birth led to very severe rickets lesions at the age of 7 weeks. This is an argument for the role of hyperparathyroidism-induced vitamin depletion in the lesions observed and in the maintenance of secondary hyperparathyroidism. Analysis of 10 previously reported cases reveals the severity of the calcium deficiency induced in the fetus in this manner, the frequency of prematurity, of dysmaturity. With calcium and vitamin treatment, biological and radiological findings become normal.