Hormonal monitoring of ovarian activity using the Ovarian Monitor, part I. Validation of home and laboratory results obtained during ovulatory cycles by comparison with radioimmunoassay

A study was conducted to determine the accuracy and reliability of the Home Ovarian Monitor for measuring estrone glucuronide (E1G) and pregnanediol glucuronide (PdG) during ovulatory cycles as a means of monitoring ovarian activity. Approximately 60 ovulating women in three centres collected timed specimens of urine (3h or more) for a total of six cycles each. The women measured the E1G and PdG excretion per 24h in their urine specimens using the Monitor. A local laboratory using the Monitor also measured the excretion. Urine specimens from 18 to 19 cycles were sent frozen to the WHO Reference Laboratory in London where they were analysed for E1G and PdG by the Monitor and by radioimmunoassay (RIA). The correlation coefficients between the Monitor and radioimmunoassay results obtained in London were better than 0.84 in 80% of the cycles. A urine bias caused the Monitor E1G results to be higher than those obtained by radioimmunoassay but the daily patterns were the same. In 50% of the cycles, this bias caused a delay of up to 3 days in identifying the beginning of the E1G rise compared with radioimmunoassay. Timing of the preovulatory E1G peak and the postovulatory PdG rise agreed within the experimental errors of the two systems. The study confirmed that women using the Monitor at home obtained results that were as accurate as those obtained by laboratory procedures. Careful supervision was required to maintain laboratory levels of quality control and interpretation of results.