Transient primary hypothyroidism in prematures.

Twelve sick neonates, ten of whom were prematures, were found to have transient primary hypothyroidism. Two months after cessation of treatment all those followed were found to be clinically and biochemically euthyroid. The possible etiologic factors in the pathogenesis of transient hypothyroidism of the sick prematures are discussed. Iodine deficiency is probably an important precipitating cause.