Prediction and detection of ovulation by hormonal measurements: Contribution of a new enzymatic method

Abstract

Accurate prediction or determination of ovulation would be very useful for physicians interested in contraception as well as in the treatment of infertility. Since the introduction of the basal body temperature method, extensive work was devoted to the temporal relationship of hormones during the menstrual cycle. Sequential variations of plasma hormones are concerned by most, if not all. of these studies, mainly FSH. LH, estradiol and progesterone. However very few of these studies documented the hormonal results to direct clinical or histological control of ovulation. Besides the difficulties inherent to such an observation in humans, some factors responsible for a lack of accuracy in this control cannot be ruled out: breadth of estradiol or LH peaks, existence of multiple peaks, progressive rise of progesterone, estimate of the age of corpora lutea., Despite the great facility in obtaining daily or twice a day urinary samples, urinary estrogens were not generally taken into consideration in these studies, owing to both the poor accuracy and sensitivity of estrogen determination in urine and the relative delay after which they are excreted. However if we infer from most of the results in the literature that the plasma estradiol peak occurs 24 h before the LH peak, a maximum urinary estrogen excretion is to be expected the day before LH peak, that is to say about 36 h before ovulation. A rapid, accurate and sensitive enzymatic method was recently set up in the laboratory for urinary estrone and estradiol determinations. Daily monitoring of menstrual cycles can be done and. repeated easily. The urinary estrogen patterns thus obtained are related to the other parameters of the menstrual cycle. The contribution of this method to the detection and prediction of ovulation will be estimated by correlation with direct observation of the ovaries. The preliminary data of this experiment suggests that, the pattern of variation of estradiol or estrone plus estradiol concentration in the early morning urine sample can be daily obtained in routine by using the enzymatic method. This pattern will be useful for routine monitoring of ovum maturation, management of infertility therapy by stimulation or insemination and control of its results.