Validating ovulation prediction and confirmation with the Mira monitor: blinded ultrasound and serum hormone comparison.

RESEARCH QUESTIONS: Do quantitative urinary hormone measurements on the Mira monitor predict and confirm ovulation accurately compared with ultrasound in women with regular menstrual cycles? Do Mira urine hormones correlate with serum hormones? DESIGN: This was a prospective, single-centre, blinded diagnostic accuracy study with 52 women aged 19-44 years with regular cycles (24-38 days) who tracked 153 cycles over 18 months. Daily first-morning urine was tested with the Mira monitor for follicle stimulating hormone (FSH), oestrone-3-glucuronide (E13G), luteinizing hormone (LH) and pregnanediol glucuronide (PDG). Serial transvaginal ultrasounds (890 scans) confirmed the day of ovulation. Serum hormones were measured twice per cycle. The 121 ovulatory cycles from 49 participants with sufficient index test and reference standard data were included in the final analysis. RESULTS: The Mira LH peak day strongly predicted ultrasound-confirmed ovulation (R² = 0.96, P < 0.001; intraclass correlation coefficient = 0.971), with 96% of ovulations occurring within ±1 day. The Mira PDG increase was also strongly associated with ultrasound-confirmed day of ovulation (R² = 0.87, P < 0.001). First-morning urine hormones were significantly associated with serum hormones when collected within 90 min (LH: R² = 0.92; E13G: R² = 0.73; FSH: R² = 0.61; PDG: R² = 0.75). Anovulatory cycles were identified in 11% of regularly cycling participants. CONCLUSIONS: Quantitative urinary hormone monitoring with the Mira monitor provides accurate prediction and confirmation of ovulation, with strong urine-serum associations supporting reduced reliance on serial serum draws in select patients. These findings support clinical adoption of quantitative urinary fertility monitoring.