Endocrine Abstracts

Thyroid physiology in early pregnancy is characterised by an increase of thyroxine binding globulin. This has been taken into account when using total T4 (TT4) if a ‘T3 uptake test (TUp)’ is used to derive the FTI. The American Thyroid Association Guidelines (1990) recommend ceasing the use of uptake tests, although in the USA they are still widely used. The aim of this study is to compare the TT4 and TUp to the FT4 in early gestation. TT4, TUp, FT4 and TSH were meas...