Estrone-3-glucuronide is the predominant metabolite of estradiol in urine and a urinary marker for the fertile window in women. Measurement of urinary glucuronides is a convenient, non-invasive method for detecting reproductive hormone levels compared to measuring plasma levels. Estrone-3-glucuronide, along with pregnanediol-3-glucuronide, are indicators of female reproductive health. Literature has shown high serum estrone levels, which directly correlate to urinary estrone-3-glucuronide levels, are associated with estrogen receptor-positive breast cancers. Hormone receptor status is the main factor in planning treatment and can be treated with hormone therapies, including tamoxifen and aromatase inhibitors. In addition to its role in breast cancer, circulating estrogens, including estrone metabolized from oral hormone replacement therapy, have been shown to increase thrombin generation leading to higher risk for blood clots, myocardial infarctions, deep vein thrombosis and strokes.
