At-home urine estrone-3-glucuronide quantification predicts oocyte retrieval outcomes comparably with serum estradiol

OBJECTIVE: To investigate the feasibility of monitoring urine estrone-3-glucuronide (E3G) with an at-home device during gonadotropin stimulation for in vitro fertilization and oocyte cryopreservation. DESIGN: Prospective, observational cohort study. SETTING: Private fertility clinic. PATIENT(S): Thirty patients undergoing stimulation with a gonadotropin-releasing hormone antagonist protocol for in vitro fertilization or oocyte cryopreservation. INTERVENTION(S): Daily collection of the first urine in the morning during stimulation and analysis performed at home by each patient with the Mira Fertility Tracker. MAIN OUTCOME MEASURE(S): Primary outcomes were correlation of urine E3G and serum estradiol (E2) concentrations on the day of trigger to the number of total and metaphase 2 oocytes (MII). Secondary outcomes of interest were the correlation of matched E3G and E2 measurements and the daily trends of E3G and E2 during stimulation. RESULT(S): Both urine E3G and serum E2 concentrations on the day of trigger significantly correlated with retrieval outcomes to a similar extent, with E3G demonstrating slightly higher correlation to the number of MII oocytes than that demonstrated by E2 (r = 0.485 vs. 0.391, respectively). The Pearson correlation coefficient for matched E3G and E2 levels was 0.761. The correlation coefficients of determination for daily trends of E3G and E2 during stimulation were 0.7066 and 0.6102, respectively. CONCLUSION(S): Measured on the day of trigger, urine E3G monitoring during gonadotropin stimulation was comparable with serum E2 for predicting oocyte retrieval outcomes. Matched daily samples confirmed good correlation of urine E3G and serum E2. The option of at-home estrogen monitoring with devices such as Mira offers an alternative to traditional serum monitoring that may improve patient experience. CLINICAL TRIAL REGISTRATION NUMBER: NCT05493202.