Some couples with infertility caused by disorders of sperm number or function may be successfully treated through intrauterine insemination (IUI). This is often performed during cycles in which the woman is taking fertility drugs to stimulate multiple egg development. Surgical repair of anatomic abnormalities may increase the chance of pregnancy in certain patients. However, IVF is the best treatment of infertile couples when there is severe impairment of sperm count, motility, or shape, or when sperm antibodies are present.