Objective: To assess the predictive value of monitoring urine LH at home using a rapid, colorimetric enzyme immunoassay test (Ovuquick) once every evening.
Methods: Twenty-six strictly defined normal women with no history of infertility were enrolled in studies involving urine LH tests. Each subject had transvaginal sonography and serum LH tests performed two times per day beginning in the middle of a normal menstrual cycle. All subjects performed urine LH testing at home every evening. The time of the peak serum LH measurement was considered the surge. Ovulation was determined using sonographic criteria with confirmation by normal luteal-phase progesterone levels (3 ng/mL or greater). Two clinically relevant intervals were determined: interval I, time from peak serum LH to positive urine LH, and interval II, time from positive urine LH to follicular collapse by ultrasonography.
Results: All 26 cycles examined were ovulatory, based on sonographic and progesterone level criteria. The mean time (+/- standard error of the mean [SEM]) for interval I was 2 +/- 2 hours (95% confidence interval [CI] -2 to 6). The mean time (+/- SEM) for interval II was 20 +/- 3 hours (95% CI 14-26). Positive predictive values for follicular collapse within 24 or 48 hours after positive urine LH testing were 73 and 92%, respectively.
Conclusion: Urine LH testing every evening is a reliable method of predicting ovulation within the ensuing 48 hours.