Anovulatory cycle In other cases, menstruation may be fairly regular (eumenorrhea), or more frequent (intervals < 21 days), or there may be a loss of menstrual pattern (menorrhagia, dysfunctional uterine bleeding). Normal menstrual bleeding in the ovulatory cycle is a result of a decline in progesterone due to the demise of the corpus luteum. It is thus a progesterone withdrawal bleeding. As there is no progesterone in the anovulatory cycle, bleeding is caused by the inability of estrogen — that needs to be present to stimulate the endometrium in the first place — to support a growing endometrium. Anovulatory bleeding is hence
Menstrual cycle half months postpartum. There is a wide range of response among individual breastfeeding women, however, with some experiencing return of menstruation at two months and others remaining amenorrheic for up to 42 months postpartum. The word "menstruation" is etymologically related to "moon". The terms "menstruation" and "menses" are derived from the Latin "mensis" (month), which in turn relates to the Greek "mene" (moon) and to the roots of the English words "month" and "moon". Even though the average length of the human menstrual cycle is similar to that of the lunar cycle, in modern humans there is no relation between