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PROGRESS IN HUMAN REPRODUCTION RESEARCH. 1992; (22):8.The WHO Special Programme on Research, Development and Research Training in Human Reproduction and diagnostic companies conduct research into the development of a simple, accurate, robust, home based method which predicts ovulation. A prolonged rise in the excretion product of estradiol in the uterine indicates that ovulation will soon follow A similar rise in serum estradiol levels also occurs several days before ovulation. Researchers in Melbourne, Australia have created an uncomplicated tool to measure the most plentiful estradiol excretion product, estrone glucuronide, and the progesterone excretion product, pregnanediol glucuronide, whose rising levels indicate the end of the fertile period. In 1991, WHO and the Australian researchers began a multicenter studying comparing this instrument with the sign and symptoms observed in traditional natural family planning methods. As of mid 1992, results were not yet available. The ability to determine the beginning and the end of the fertile period makes this potential tool especially promising. WHO is supporting another multicenter study testing for a decline of the enzyme guaiacol peroxidase in cervical mucus as a marker of approaching ovulation. It is difficult to test for forthcoming ovulation in premenopausal women, because they do not always ovulate their menstrual cycles. A WHO study looked at the association between ovarian hormone secretion an symptothermal indicators of fertility in 36 premenopausal women (177 menstrual cycles). Around 33% of the women regular menstrual cycles that may have been fertile, around 19% experienced no hormonal changes indicating fertility during their cycles, and the rest of the woman had a combination of both. Further traditional symptothermal markers could not distinguish the 2 different types of cycles.
In: Diczfalusy, E., ed. Regulation of human fertility. (Proceedings of the WHO Symposium on Advances in Fertility Regulation, Moscow, USSR, November 16-19, 1976) Copenhagan, Denmark, Scriptor, 1977. p. 21-71This chapter reviews the hormonal changes which occur during the menstrual cycle. During the last days of the preceeding menstrual cycle, plasma levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) increase. Follicular phase is characterized by gradually increasing estrogens. A few days preceding the LH surge, some little understood changes in estradiol, LH, and 17-hydroxyprogesterone, on one hand, and ACTH, cortisol, and aldosterone, on the other, occur. Evidence indicates that the estradiol peak occurs first, followed by a simultaneous rise and fall in LH and 17-hydroxyprogesterone values. The peak period of LH is about 32-44 hours long, during which time a rise in progesterone levels takes place. Other pituitary and steroid hormones (human chorionic gonadotropin, ACTH, prolactin, testosterine, androstenedione, cortisol, and aldosterone) show elevated levels during the periovulatory period. Ovulation occurs 16-48 hours after LH peak. The period following LH surge is characterized by rapidly increasing levels of progesterone, 17-hydroxyprogesterone, and 20-alpha-dihydroprogesterone, accompanied by moderately increasing estrogen levels to form the typical luteal-phase hormonal pattern. A luteal increase occurs also in levels of several other hormones, ranging from renin activity to angiotension, or from pregninolone to aldosterone. The last part of the luteal phase is characterized by rapidly declining levels of peripheral hormones. The perimenstrual phase around onset of heavy bleeding is characterized by gradually decreasing levels of progesterone, 20-alpha-hydroprogesterone, estradiol, and testosterone, associated with an incipient rise in LH and FSH levels.