Glossary · Conditions

Anovulation

Definition: Anovulation is the failure of an ovarian follicle to release an egg during a menstrual cycle. Anovulatory cycles produce unopposed estrogen exposure (no luteal-phase progesterone) and are common in perimenopause as well as in conditions like PCOS.

Detailed definition

Anovulation refers to a menstrual cycle in which ovulation does not occur. The follicle may develop and produce estrogen without releasing an egg, producing prolonged unopposed estrogen exposure to the endometrium and absence of luteal-phase progesterone. Bleeding from anovulatory cycles can be irregular, heavy, or prolonged. Anovulation is the dominant pattern in late perimenopause, in PCOS, in hypothalamic amenorrhea, and in some thyroid and pituitary disorders.

Why it matters in menopause

In late-perimenopausal women with heavy or irregular bleeding, anovulation is often the underlying mechanism. Treatment options include the LNG-IUD, cyclic progesterone, or combined hormonal contraception in younger perimenopausal women.

Sources

External references: Wikipedia.

← Back to full glossary