Correlation between urinary oestrogen levels determined by haemagglutination inhibition reaction and serum oestradiol levels determined by radioimmunoassay.

Measurement of urinary or blood oestrogen is essential for a precise monitoring of follicular development in gonadotrophin therapy. Blood oestradiol levels are considered most accurately to reflect follicular maturation. Although radioimmunoassays (RIA) for oestradiol yielding rapid results are now available, they require qualified technicians and equipment for RIA. Recently, a simple, rapid method for determining urinary total oestrogen has been developed by Mochida Pharmaceutical Co. Ltd., Japan. To determine whether this kit may be applicable to monitoring gonadotrophin therapy, urinary total oestrogen concentrations measured by the kit were compared with serum oestradiol levels determined by RIA in patients who were treated with gonadotrophin. Urinary total oestrogen concentrations in samples obtained either at 07.00 h (first morning urine specimen) or at 09.00 h significantly correlated with serum oestradiol levels. Thus, urinary total oestrogen concentrations determined by the kit appear to reflect follicular development accurately, and are considered applicable to monitoring gonadotrophin therapy. Correction of the urinary total oestrogen concentrations by the creatinine level significantly improved the correlation between urinary total oestrogen values and serum oestradiol levels. Therefore, the primary total oestrogen values should be corrected by the creatinine level.