Knowra Anovulation Anovulation Anovulation is the absence of ovulation during a menstrual cycle. It can occur occasionally or persistently and may disrupt menstrual bleeding and fertility.
Hypothalamic–pituitary–ovarian axis : The hormonal signaling system linking the hypothalamus, pituitary gland, and ovaries to regulate reproductive function. Disruption anywhere in this signaling loop can prevent the hormonal events that trigger ovulation.
Menstrual cycle : The recurring hormonal and reproductive changes that prepare the body for possible pregnancy. Bleeding patterns provide clues to ovulation, though bleeding alone does not prove it occurred.
Anovulatory bleeding : Uterine bleeding that occurs without preceding ovulation, often because the endometrium is exposed to estrogen without regular progesterone opposition. It explains why bleeding can occur even when no ovulation took place.
Oligo-ovulation : Infrequent or irregular ovulation, with longer-than-usual intervals between ovulatory cycles. Unlike complete absence of ovulation in a cycle, ovulation occurs intermittently.
Gonadotropin-releasing hormone : A hypothalamic hormone released in pulses that stimulates pituitary secretion of luteinizing hormone and follicle-stimulating hormone. Abnormal pulse patterns can impair the pituitary signals needed for follicle development and ovulation.
Infertility : A reproductive condition in which pregnancy has not occurred after a defined period of regular unprotected intercourse. Anovulation is a common, potentially treatable cause of difficulty conceiving.
Amenorrhea : The absence of menstrual bleeding for a clinically significant interval. Persistent anovulation may present as absent periods, though amenorrhea has other causes.
Ovulation : The release of a mature egg from an ovarian follicle, usually after a surge in luteinizing hormone. It is the reproductive event absent in anovulatory cycles.
Luteinizing hormone : A pituitary hormone whose mid-cycle surge triggers ovulation and supports progesterone production afterward. A missing or inadequate surge can leave a mature follicle unruptured.
Polycystic ovary syndrome : A hormonal and metabolic disorder often associated with irregular ovulation, androgen excess, and polycystic ovarian appearance. It is a frequent cause of persistent anovulation in reproductive-age people.
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