Amenorrhea (uh-men-o-REE-uh) is the absence of menstruation one or more missed menstrual periods. Women who have missed at least three menstrual periods in a row have amenorrhea, as do girls who haven't begun menstruation by age 15. The most common cause of amenorrhea is pregnancy. Other causes of amenorrhea include problems with the reproductive organs or with the glands that help regulate hormone levels.Amenorrhoea is the term for the lack of menstrual function in women. This means that the woman experiences no menstrual bleeds and will be infertile. Amenorrhoea may be primary amenorrhoea or secondary amenorrhoea. Primary amenorrhoea is when the woman has never had a menstrual cycle or menstrual bleed. It occurs in about 3 in 1000 women. Secondary amenorrhoea is when a woman has had menstrual periods in the past but these have now stopped. This occurs in about 3 in 100 women. LH, FSH, Prolactin, beta-hCG