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

Abstract

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.

Timing intercourse to achieve pregnancy Current evidence

“…In no cases did ovulation occur before "peak" fertility. 21 A separate validation study found close correlation between the results of the monitor and laboratory measurements from urine. In 66% of cycles, the LH surge detected by the monitor was on the day of the LH surge detected by laboratory analysis, whereas in 24% it occurred on the day before.…”

Comparison between the different methods developed for determining the onset of the LH surge in urine during the human menstrual cycle

“…The study of hormonal profiles in urine during the menstrual cycle has proved to be very valuable in understanding menstrual cycle dynamics, as well as variability in ovulation [19,27,28]. Likewise, urinary hormone testing has become an established application for personal monitoring of fertility awareness [9]. Both temperature and hormonal analysis using repeated measurements in menstrual cycles are currently under intensive research as part of the evolving field of digital signal tracking in gynaecological endocrinology [21].…”

“…In addition, urinary peak LH day can differ according to the assay used to measure LH in urine, with those detecting beta-core LH (LH-bc) identifying a peak day at least 1 day after assays that do not detect LH-bc [4]. Identification of the day of the urinary LH surge does not appear to be influenced by the assay used, and provides 24-36 h warning of impending ovulation [7][8][9][10], therefore making it an excellent parameter to measure in order to provide prospective information regarding ovulation. Therefore, it is important to have a well-validated method for assignment of the LH surge and to examine retrospective datasets to provide information on population variability of LH surge.…”

Variability in the hormonally estimated fertile phase of the menstrual cycle

“…The rise of estradiol in plasma or a metabolite in urine has been suggested as an indicator to the start of the probable fertile phase (15). Other researchers have demonstrated that the CEFM levels of LH and E3G coincide well with the laboratory measurements in defining the potentially fertile period, and found that they follow the increasing concentrations of serum estradiol on the days before ovulation (12,16). They also found the mode warning of ovulation by the CEFM high was 6 days (range, 0-20 days) (12).…”