A fertility determining system employing hormone level measuring apparatus on
selected
days in a menstrual cycle to determine the levels of analytes, i.e., estrone-3-glucuronide
("E3G") and luteinizing hormone ("LH"), in early morning urine. The fertility/infertility
signalling algorithm relies upon data characterizing the user earlier in that menstrual
cycle, and also upon her analyte pattern in past recent cycles. At a point in a
menstrual cycle which is user-dependent, the early morning E3G urine level is compared
against the lower E3G level earlier in the cycle. The beginning of the fertile
period is signalled when a sufficient E3G increase occurs. The end of the fertile
period (and, correspondingly, the reestablishment of a period requiring no contraception)
is signalled a period after the LH surge. In the absence of an LH surge in any
subject, the end of the fertile phase is signalled a period of time following the
peak of the E3G urinary metabolite of estradiol.
