Stability of urinary female reproductive hormones stored under various conditions

Urinary reproductive hormones afford specific and sensitive evaluation of female reproductive potential in epidemiologic and clinical settings. The goal of this study was to characterize the stability of urinary luteinizing hormone, follicle stimulating hormone, estrone 3-glucuronide, pregnanediol 3-glucuronide, and creatinine during storage as functions of time, temperature, and additives. After 2 weeks with no additives, activity of the four analytes, relative to initial concentrations, ranged from 91.9 to 102.8% at 4 degrees C, 35.1 to 89.6% at 25 degrees C, and 7.5 to 66.9% at 37 degrees C. Antimicrobial additives did not consistently improve stability. Analyte activity for samples stored with no additives for 24 weeks at -80 degrees C ranged from 69.0 to 101.2%. Glycerol and bovine serum albumin improved analyte stability; activity ranged from 91.1 to 106.3%. Other additives were ineffective. These results reveal conditions for storing reproductive hormone analytes in urine during epidemiologic field studies.