PERIMENOPAUSE: Ovarian accumulation and productiveness turn down brusquely following the age of 35 and doubly sharply throughout perimenopause; lessening of main follicles, a procedure that starts prior to delivery, happens gradually in anticipation of menopause. Follicle-stimulating hormone (FSH) intensity goes up, because of transformed folliculogenesis and lessened inhibin discharge. Different to the again and again high FSH and little estradiol levels observed in menopause, perimenopause is regarded as by “irregularly irregular” hormone intensities. The tendency for anovulatory cycles can create a hyperestrogenic, hypoprogestagenic situation that may be the cause of the enlarged occurrence of endometrial hyperplasia or carcinoma, leiomyoma and uterine polyps seen amongst women in the age of perimenopausal. With transition into menopause, oestradiol level falls markedly, whereas oestrone intensities are comparatively conserved and it reflects secondary aromatization of adrenal and ovarian androgens.
POSTMENOPAUSE: The menopause is defined as the final episode of menstrual bleeding in women. Menopause is the consequence of exhaustion of ovarian follicles, a process that begins during foetal development. The median age of women at the time of cessation of menstrual bleeding is 50 to 51 years. Preceding the menopause, the pattern of menstrual cycles is variable, but the interval between menses usually becomes shorter, as follicular recruitment is hastened by increases in FSH. Day 3 FSH and 17?-estradiol (E2) levels are often elevated. Ovulatory cycles continue for some period of time, and then anovulation becomes common.
Hormone changes during perimenopause and postmenopause
The postmenopausal women have small and wrinkled ovaries, and the residual cells are predominantly stromal. Oestrogen and androgen levels in plasma are reduced but not absent. Before the menopause, plasma androstenedione is derived almost equally from the adrenals and the ovaries; after menopause, the ovarian contribution ceases so that the plasma levels of androstenedione fall by 50%. However, the menopausal ovary continues to secrete testosterone, presumably formed in stromal cells. After menopause, extra glandular oestrogen formation is the major pathway for oestrogen synthesis. Because adipose tissue is a major site of extra glandular oestrogen production, peripheral oestrogen formation may actually be enhanced in obese postmenopausal women. The predominant oestrogen formed is 0estrone rather than oestradiol.
