There are several different reasons for anovulation (not developing and releasing an egg). Polycystic Ovarian Syndrome (PCOS) is the most common cause. In other cases the signals from the brain to the ovary are interrupted such that egg development does not proceed. General infertility testing most often reveals the causes of anovulation and aids in directing the appropriate treatments. Oral medications and injectable gonadotrophins are used to stimulate the ovaries to produce the eggs.