Prediction of ovulation was established by correlation of clinical parameters, follicular development by ultrasound, and estradiol, progesterone, and luteinizing hormone (LH) determination in 71 menstrual cycles. Laparoscopic follicular aspiration was accomplished in 41 of those cycles. A 28-hour interval from the ascending limb of the LH seems to be the "ideal time" for retrieval of a preovulatory oocyte. The variability in the amount of LH to which the follicle is exposed during the LH surge seems to indicate that there is a relatively low specific value necessary for ovulation. Ovulation occurs approximately 10 +/- 5 hours from the LH peak. Progesterone occurs in relation to the LH surge and is helpful for the retrospective analysis of the menstrual cycle.
PIP: There still is not a single reliable parameter for ovulation prediction. This paper reports on the authors' experience in predicting ovulation by the correlation of clinical parameters and steroid hormone values with estimates of follicle size by ultrasound. 32 healthy women were investigated for a total of 85 cycles. 71 cycles were satisfactorily completed and analyzed. Serum estradiol, the initial rise of progesterone, and the rise in serum luteinizing hormone (LH) were measured daily and every 4 hours during the preovulatory and ovulatory period. Daily basal body temperature and changes in cervical mucus were observed as well. Ovulation was estimated on the basis of clinical parameters, shift of temperature, disappearance of the dominant follicle at ultrasound, and serum progesterone values higher than 1.25 ng/ml. In 41 cycles laparoscopy was performed and aspiration of the dominant follicle carried out; then correlation was made with progesterone values at aspiration time and with the characteristics of the oocyte. A 28-hour interval from the ascending limb of LH seems to be the ideal time for retrieval of a preovulatory oocyte. Ovulation occurs approximately 5-15 hours from LH peak; progesterone rise is related to LH surge, but because of the time involved, progesterone assay does not help in the prediction of ovulation. This study shows that prediction of ovulation is feasible, and that ultrasound is an indispensable complementary tool for following the development of the follicle and for determining the side upon which ovulation will occur.