There are women who do not ovulate spontaneously and they need fertility drugs to stimulate the eggs to maturity and the ovaries to release the eggs. Ovarian function is dependant on a functioning hypothalamic-pituitary-ovarian axis and any problem affecting the axis would result in failure to ovulate or anovulation. Thus dysfunction of the hypothalamus of the brain as caused by stress or extreme weight loss (anorexia nervosa, ballerinas), pituitary conditions like hyperprolactinemia or polycystic ovary syndrome of the ovaries can cause anovulation. Where indicated and appropriate, fertility medications can be given either orally (clomiphene, letrozole, bromocriptine) or by injections (follicle stimulating hormone, human chorionic hormone) to stimulate the eggs to develop to maturity and the ovaries to ovulate. The couple are then instructed on the best time to conceive naturally or sometimes with the help of intrauterine insemination in a programme called superovulation and intrauterine insemination (SOIUI) programme.