The effect of triiodothyronine administration on the elevated protein-bound iodine level in human pregnancy

Abstract

1.1. Depression of the elevated PBI level of pregnant women followed the administration of triiodothyronine in the second and third trimesters.2.2. The data reveal that the pituitary-thyroid relation is normally responsive in pregnancy, and that the elevation in PBI is not due to the abnormal relation seen in hyperthyroidism.3.3. The data tend to exclude the possibility of more than limited placental secretion of thyrotropin.4.4. The implications are discussed of the finding that larger doses of triiodothyronine were required to suppress the PBI level in the last trimester of pregnancy than in the preceding trimester.