Female hypogonadism: evaluation of the hypothalamic-pituitary-ovarian axis.

Female hypogonadism refers to deficient or abnormal function of the hypothalamic-pituitary-ovarian axis that clinically presents with menstrual cycle disturbances. Female hypogonadism can be due to a congenital or acquired cause, and the defect can be at the level of the hypothalamus, pituitary or ovary. A careful history, physical exam and selected laboratory testing can often determine the locus of the defect and whether it results from a structural or hormonal problem. Laboratory testing generally relies on basal hormone levels; however, timing of blood sampling in relation to menses is important to interpretation of the data.