[Etiology of congenital hypothyroidism]

Iodine deficiency, intrathyroidal defects of thyroxine synthesis and morphological defects of the thyroid gland are the causes for connatal hypothyroidism of various degrees. Morphological defects include the most severe forms of cretinism due to aplasia of the gland as well as various more milder forms following application of iodine or antithyroidal drugs to the mother or TSH deficiency of the newborn. Due to general TSH-screening programs, more will be learned about the still not fully understandable etiology of connatal hypothyroidism.