Thyroid function during pregnancy with special reference to hydatidiform mole and hyperemesis.

The thyroid function tests, serum protein-bound iodine (PBI), serum triiodothyronine reaction (T3-test) and serum cholesterol were measured in three groups of pregnant women: 1) 57 with normal pregnancy, 2) 35 with hyperemesis and 3) 14 with hydatidiform mole. A pattern of high values of PBI and T3-test and relatively low values of cholesterol in most of the patients with hydatidiform mole, and in almost one third of the patients with hyperemesis was found. A positive correlation of the volume of molar tissue and the values of PBI was observed. The treatment of patients with hyperemesis mostly resulted in normalisation of the thyroid function tests, while this was not the case in patients with mole. It is suggested that there might be a common cause of the thyroid stimulation in patients with mole and hyperemesis.