Prediction of human ovulation by rapid luteinizing hormone (LH) radioimmunoassay and ovarian ultrasonography.

Accurate prediction of the time of ovulation is essential for the recovery of a mature oocyte for in vitro fertilization (IVF). The preovulatory luteinizing hormone (LH) surge can be considered the most reliable hormonal change closely related to ovulation. With the use of a rapid LH assay and ovarian ultrasonography, it now appears possible to predict quite accurately the time of ovulation, provided that these technologies are appropriately applied. Therefore, we have used a newly standarized rapid (3-hour) LH radioimmunoassay (RIA) for serial estimation of preovulatory serum LH surge. So far, 21 women have come to our center daily during their 5-day preovulatory period. Blood samples were taken daily every 3 to 5 hours between 7:00 A.M. and 11:00 P.M. Ovarian ultrasonic scans were performed one to three times daily depending on the day of the cycle and the serum LH level. Data show that there is a significant variation in the mean preovulatory follicular size, in the duration of the LH surge, and in the time interval between the initial rise of LH surge and the estimated time of ovulation. Results obtained from six women studied during two to four cycles indicate that each woman has a distinctive hormonal and ultrasonic pattern that appears to be reproducible. Thus it is recommended that such a pattern be appropriately evaluated before attempting laparoscopy for recovery of a mature human oocyte.