Accuracy of the ovulon fertility monitor to predict and detect ovulation

The purpose of this pilot study was to correlate the three biologic markers of the Ovulon fertility monitor (a long-term predictive peak about 6 days before ovulation, a short-term predictive peak about 1 day before ovulation, and a nadir at the time of ovulation) with the peak in cervical mucus and the luteinizing hormone (LH) surge in the urine. Ten volunteer subjects (mean age 30.2 years) monitored their cervical-vaginal mucus, the surge of LH in the urine with a home assay test, and their vaginal electrical readings (with Ovulon monitors) on a daily basis for one to four menstrual cycles. In 19 of the 21 cycles that indicated a LH surge, there was a strong positive correlation between the LH surge and the peak of cervical-vaginal mucus (r = 0.96, P less than or equal to .01), and between the LH surge and both the Ovulon nadir and Ovulon short-term predictive peak (r = 0.84, P less than or equal to .01), and a modest positive correlation between the long-term Ovulon predictive peak and the LH surge (r = 0.62, P less than or equal to .01). The time of optimal fertility as determined by the peak in cervical mucus, the LH surge, and the Ovulon was similar. The Ovulon has potential as a reusable device to help women determine their fertile period. (C) 1998 by the American College of Nurse-Midwives.