A condition in which the ovaries stop working and menstrual periods stop before age 40. This can cause fertility problems and symptoms of menopause. Primary ovarian insufficiency means the ovaries do not function normally. This may be because they have been removed by surgery, or it may be caused by some cancer treatments and certain diseases or genetic conditions. Some women with primary ovarian insufficiency sometimes have menstrual periods and may be able to have children. Also called premature ovarian failure.