Anovulatory cycle Anovulatory cycle The anovulatory cycle is a menstrual cycle characterized by varying degrees of menstrual intervals and the absence of ovulation and a luteal phase. In the absence of ovulation, there will be infertility. While the normal menstrual cycle in the human typically lasts 4 weeks (28 days, range 24–35 days) and consists of a follicular phase, ovulation, and a luteal phase, followed by either menstruation or pregnancy, the anovulatory cycle has cycle lengths of varying degrees. In many circumstances, menstrual intervals are prolonged exceeding 35 days leading to oligomenorrhea (cycle >35 – 180 days interval), or even longer, amenorrhea.
Estrous cycle almost any arbitrary moment (comparable with humans, who, however, have a menstrual cycle in place of an estrous cycle). Generally speaking, the timing of estrus is coordinated with seasonal availability of food and other circumstances such as migration, predation etc., the goal being to maximize the offspring's chances of survival. Some species are able to modify their estral timing in response to external conditions. The female cat in heat has an estrus of 14 to 21 days and is generally characterized as an induced ovulator, in that coitus induces ovulation. However, various incidents of spontaneous ovulation have been documented in