Simplified LH-rise method to time oocyte recovery for in vitro fertilization

The aim of this study was to assess the usefulness of a simplified method to detect the LH rise. The mean plus two standard deviations of the LH values in the prevulatory period was 6.70 +/- 3.45 mIU/mL in a group of women in whom at least one mature oocyte fertilized and cleaved. For practical purposes, an absolute LH value of 15 mIU/mL was considered the start of the rise using the LH graph, and was designated the LH rise value. In 76 patients who experienced a spontaneous LH surge (detected by daily sampling at 08:00, 15:00, 23:00), oocyte recovery was timed for 32 to 35 hours after the LH rise using this simplified method. The outcome of IVF-ET in these patients was comparable to that of the control patients in whom hCG was administered. Graphs were drawn retrospectively using only two (08:00 and 23:00) LH values obtained for each day for each patient and the start of the LH rise was plotted. Most patients (66%) would have had oocyte recovery at the same time whether they had two or three daily LH values. The remaining patients would still have undergone oocyte recovery at an acceptable time (within +/- 6 hours). It was concluded that this simple method accurately identifies the onset of the spontaneous LH rise and may be effected by twice-daily LH sampling.