4-hour urinary and serum immunofluorimetric assay for luteinizing hormone to detect onset of preovulatory LH surge.

The initial surge of LH is an important preovulatory event. The validity of a time-resolved immunofluorimetric assay method for determining LH both on the samples of serum and urine are reported in our study. A good correlation exists between the serum and urinary LH with the presence of a shorter interval in the length of the LH increase in the urinary dosage in respect to the serum dosage. There emerges when comparing the RIA and IFMA techniques that a good correlation exists both in the urinary and in the serum samples. However the values found with the IFMA method are on the average inferior (ca. 50%) in respect to those obtained with the RIA technique.