Monitoring techniques to predict and detect ovulation

This study was designed to evaluate the accuracy of various methods in predicting and detecting ovulation in 14 spontaneous and 17 clomiphene citrate (CC)-induced cycles. From cycle day 11 all subjects (n = 27) were followed with daily transvaginal ultrasound; rapid measurement of serum luteinizing hormone (LH) and estradiol (E2); determination of urinary LH with First Response (Tambrands Inc., Palmer, MA) and Ovustick (Monoclonal Antibodies, Inc., Mountain View, CA) kits; and recording of basal body temperature (BBT). The results demonstrated that transvaginal ultrasound detected ovulation in all cycles. Mean daily serum LH levels were similar in both groups, and peak values of 40 mIU/ml or greater preceded the day of ovulation in all cycles. Serum E2 peak was significantly greater in CC cycles (961 +/- 96 versus 463 +/- 39 pg/ml) (P less than 0.01) and preceded the LH peak in 97% of the cycles. First Response and Ovustick predicted ovulation in 53.3% and 87.5% of the cycles, respectively (P less than 0.01). BBT nadir predicted the day of ovulation in only 10% of cycles. In conclusion, this study revealed that transvaginal ultrasound is an excellent method for detection of ovulation and that Ovustick is a very useful method for prediction of the day of ovulation.