Enzyme immunoassay method for total alpha gonadotropin in human urine samples

Area of Science:

• Reproductive Endocrinology
• Biochemistry
• Assay Development

Background:

• Accurate monitoring of the ovulatory cycle is crucial for fertility treatments.
• Urinary luteinizing hormone (LH) metabolite analysis offers a non-invasive method for ovulation prediction.
• Challenges exist in preserving and analyzing urine samples collected outside a clinical setting.

Purpose of the Study:

• To develop and validate a reliable assay for urinary LH metabolites.
• To enable the use of frozen-thawed urine samples for LH analysis.
• To establish a practical method for ovulation detection using self-collected urine.

Main Methods:

• Two-part study: (1) identification of urinary LH metabolites, (2) daily analysis of matched blood and urine samples over 26 menstrual cycles.
• Inclusion of women with normal ovarian function undergoing artificial insemination.
• Measurement of serum LH and urinary LH metabolites from daily samples.

Main Results:

• A strong correlation was observed between the midcycle serum LH peak and urinary LH metabolite measurements in frozen-thawed urine.
• The developed assay successfully detected the midcycle LH surge using stored urine samples.
• Daily measurements from 25 ovulatory cycles provided robust validation data.

Conclusions:

• A straightforward enzyme assay for LH/LH-alpha is effective for detecting the midcycle LH surge in frozen-thawed urine.
• This assay has significant practical applications for analyzing self-collected, stored urine samples.
• The method facilitates accurate determination of the day of ovulation, particularly in remote or self-managed settings.