Timing of urinary estrone-3-glucuronide tests

Background

• The onset of a woman`s fertile phase can be identified by an increase in concentration of urinary metabolites of estradiol, including E1-3G (estrone-3-glucuronide).
• Home ovulation tests typically detect the lutenising hormone (LH) surge, which identifies the day before and day of ovulation.
• Some tests also measure E1-3G to identify the user`s wider fertile phase.
• Such tests require users to test the first morning void.
• The consequences of testing at different times of the day are not known.

Methods

• Women aged 18-45 with natural menstrual cycles (n=19) were required to collect and measure volume of every single void of urine for one entire menstrual cycle.
• Creatinine (Cobas Miras™) and E1-3G and LH (AutoDELFIA™) were measured on all 1732 samples.
• Trial registration number NCT:01577147.

Results

• Women voided a median of 6 urine samples per day (min to max; 2-12).
• LH surge day ranged from day 10-25 (mean 13.9).
• When considering only first morning void urine, the E1-3G rise was a mean of 1.94 days in advance of the LH surge.
• Creatinine correction had minimal impact, with the mean time from E1-3G rise to LH surge being 2.28 days. Figure 1 shows the effect of creatinine correction on E1-3G profile of first morning urine samples from 3 volunteers.