Amenorrhea due to loss of ovarian function before the age of 40. Primary ovarian inssuficiency (POI) is a state of female hypergonadotropic hypogonadism. It can manifest as primary amenorrhea with onset before menarche or secondary amenorrhea.

Abnormally late or absent menarche in a female with normal secondary sexual characteristics.

The cessation of menstruation for six months or more in a female that is not pregnant, breastfeeding or menopausal.

A developmental disorder characterized by the progressive loss of primordial germ cells in the developing ovaries of an embryo, leading to hypoplastic ovaries composed of wavy connective tissue with occasional clumps of granulosa cells, and frequently mesonephric or hilar cells.

Developmental hypoplasia of the ovary.

A count of antral follicles that is lower than normal for age.