Re-examining steroid hormone metabolites as ovulation markers using monoclonal antibodies

Plasma progesterone and plasma estradiol levels are commonly used to monitor ovulation in women although for the adequate documentation of ovulation the expense and discomfort of multiple venipuncture sampling may be required. Accurate and definitive information on ovulation in women can be obtained by the simple measurement of metabolites of progesterone and estradiol in early morning urine samples. These analyses have been made possible by the use of our own highly specific monoclonal antibodies to both pregnanediol-3-glucuronide (P-3-G) and estrone-3-glucuronide (E-3-G) and the development of simple, direct, automated enzyme-linked immunosorbent assays. Sequential sampling and the generation of ovulation profiles allows detection of ovulation and identification of the infertile/fertile phases of the cycle for either planned pregnancies or natural family planning. Aberrations in ovulation are easily detected as is documentation of the transition to menopause. The use of sequential, spaced, early morning urine samples for P-3-G and E-3-G allows accurate assessment of ovulatory function rather than relying on the usual single plasma sampling. The data presented also show that the direct determination of plasma pregnanediol-3-glucuronide in plasma is as informative as plasma progesterone measurement.