Clinical Aspects of Menstruation

Extract

[...] CLINICAL ASPECTS OF MENSTRUATION Menstruation is the periodic discharge of blood, mucus, and cellular debris from the uterine mucosa. Menses occur at more or less regular, cyclical, and predictable intervals from menarche to menopause except during pregnancy, lactation, anovulation, or pharmacological intervention. It is convenient and more descriptive to use the term menstruation to refer to the bleeding that accompanies progesterone withdrawal after ovulation with nonfertile cycles, and to refer to other episodes of endometrial hemorrhage in nonpregnant women as uterine or endometrial bleeding. [...]

[...] Gunn and co-workers (1937), in a study of 479 normal British women, found that the typical difference between the shortest and the longest cycle was 8 or 9 days. In 30 percent of women, it was more than 13 days, but it was never fewer than 2 days in any woman. Arey found that among average adult women, one third of menstrual cycles departed by more than 2 days from the mean of the lengths of all cycles. In Arey's analysis of 5322 cycles in 485 normal women, an average interval of 28.4 days was estimated; his finding for the average cycle length in pubertal girls was longer days. [...]

[...] The volume of blood lost with each menstruation is relatively small, especially considering that the surface area of the endometrium of normal uteri of nonpregnant women is 10 to 45 cm2 (Chimbira and colleagues, 1980). Therefore, there must be an effective means of hemostasis in endometrium during menstruation. The control of blood loss likely is not induced by myometrial contractions to compress uterine vessels, as is the case after delivery of the fetus and placenta. Excessive blood loss with menstruation is common, however, in women with coagulation or platelet disorders. [...]