Objective: To determine the presence of FSH in unextracted urine of perimenopausal women using a microparticle enzyme immunoassay kit on an AxSYM random access immunoassay analyzer.
Design: Controlled descriptive study.
Setting: A large teaching hospital and infertility clinic.
Patient(s): Forty perimenopausal women aged 32-55 years admitted to our clinic for a gynecological operation.
Intervention(s): None.
Main outcome measure(s): Mean serum FSH level and urinary FSH in early-morning urine, in a random void urine sample, and in 24-hour urine on the same day. FSH in urine on the day of excretion and 1 and 4 weeks thereafter, stored under various conditions. FSH in urine before and after extraction.
Result(s): The Pearson's correlation coefficient between mean serum FSH levels and urinary FSH in early morning urine was 0.904, in a random void 0.915, and in 24-hour urine 0.857. Determination of optimal storage conditions revealed that urine was best kept at 4 degrees C without any additive. The correlation between FSH in extracted and unextracted urine was 98.9%.
Conclusion(s): In perimenopausal women, FSH can be reliably measured in unextracted urine. The correlation between urinary FSH and a random void urine sample and mean FSH from a serial serum sample is very high. Urine can be stored for 4 weeks at 4 degrees C without loss of FSH immunoreactivity.