[Maternal and infant thyroid gland during pregnancy and in the postpartum period].

A survey is given of the clinically relevant changes in the thyroid hormone balance of the maternal organism. The total concentrations of thyroid hormone may on account of the increased carrier protein level be incorrectly interpreted in the sense of a hyperthyroidism. The latent hormone binding capacity, however, may by mistake indicate a hypothyroidism. For the determination of the functional position, therefore, a statement about the free hormone fraction is necessary. The TRH-test is evident in pregnancy. Beginning with the 12th week of pregnancy the fetal thyroid gland produces thyroid hormones, from the 16th to the 20th week of pregnancy the fetus is autonomous; and the pituitary gland-thyroid gland-axis is able to function nearly from the 20th week of pregnancy. The consequences resulting from this for the therapy of a disease of the thyroid gland of the mother are explained. Due to a massive TSH-flow with the birth typical changes of the hormone levels develop which may be used for the early recognition of the congenital hypothyroidism (TSH-screening). Possibilities of the diagnosis of the prenatal function of the thyroid gland as well as of the therapy of hypothyroidism are discussed.