Urinary estradiol-17-beta-glucuronide assay for gonadotropin therapy

Area of Science:

• Reproductive endocrinology
• Clinical chemistry

Background:

• Monitoring ovulation induction with human menopausal gonadotropin (hMG) is crucial for successful fertility treatment.
• Accurate assessment of ovarian response is necessary to time human chorionic gonadotropin (hCG) administration.
• Urinary estradiol-17 beta-glucuronide (E2-17G) is a potential biomarker for monitoring estrogen levels.

Purpose of the Study:

• To evaluate the utility of direct radioimmunoassay for urinary E2-17G in monitoring ovulation induction with hMG.
• To assess the correlation between urinary E2-17G and serum estrogens during hMG treatment.
• To determine if urinary E2-17G can reliably guide clinical decisions for hCG administration.

Main Methods:

• Daily measurements of serum estrogens and urinary E2-17G in 21 women undergoing 32 hMG treatment cycles.
• Urinary E2-17G was analyzed in both 24-hour and overnight urine specimens.
• Radioimmunoassay was used for both serum estrogen and direct urinary E2-17G quantification.

Main Results:

• A significant positive correlation was observed between serum estrogens and urinary E2-17G excretion (24-hour and overnight).
• Creatinine correction did not significantly improve the correlation between urinary E2-17G and serum estrogens.
• Significant variability in urinary E2-17G levels during the preovulatory phase (serum estrogens 500-1000 pg/ml) precluded definitive clinical decisions regarding hCG administration.

Conclusions:

• While urinary E2-17G measured by direct radioimmunoassay correlates with serum estrogens, its significant variability limits its clinical applicability for triggering ovulation.
• The observed variability indicates that correlation alone is insufficient for a new method to replace established protocols.
• Further research is needed to establish the reliability of direct urinary E2-17G radioimmunoassays, particularly in overnight collections, for monitoring hMG therapy.