Prediction of ovulation by urinary hormone measurements with the home use ClearPlan Fertility Monitor: comparison with transvaginal ultrasound scans and serum hormone measurements

Hum Reprod. 2000 Dec;15(12):2478-82. doi: 10.1093/humrep/15.12.2478.


The timing of sexual intercourse in relation to ovulation strongly influences the chance of conception. Daily serum LH measurements or transvaginal ultrasonography are not practical to determine ovulation in consecutive cycles for an individual. A prospective study was initiated to test the home use performance of the ClearPlan Fertility Monitor (CPFM) in ovulation prediction compared with transvaginal ultrasonography and serum hormone measurements. A total of 53 women aged 18-39 years with a normal uterus and at least one ovary, cycle length between 21-42 days and not using medication which interferes with ovarian function contributed 150 cycles for analysis. One cycle was anovulatory and no LH surge, indicating peak fertility, was detected by the monitor. Of the remaining 149 cycles, 135 (90.6%) had a monitor LH surge and ultrasonographically confirmed ovulation. Ovulation was detected in 91.1% of cycles during the 2 days of CPFM peak fertility. Ovulation was observed in 51.1% of cycles 1 day and in 43.2% of cycles 2 days after the surge in serum LH. Ovulation never occurred before CPFM peak fertility or the serum LH surge day. CPFM can help women who desire pregnancy to time intercourse. It may also have potential as a diagnostic aid and for monitoring the treatment of infertility.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Estradiol / blood
  • Estrone / analogs & derivatives*
  • Estrone / urine*
  • Female
  • Fertility
  • Humans
  • Luteinizing Hormone / blood
  • Luteinizing Hormone / urine*
  • Menstrual Cycle
  • Ovarian Follicle / diagnostic imaging*
  • Ovulation Detection / instrumentation
  • Ovulation Detection / methods*
  • Prospective Studies
  • Reagent Strips
  • Ultrasonography


  • Reagent Strips
  • estrone-3-glucuronide
  • Estrone
  • Estradiol
  • Luteinizing Hormone