The history and examination alone will often point toward the diagnosis and dictate the order in which examinations should be performed. Using this approach and good common sense, laboratory examinations, expense and time can be limited to a minimum. There are four major categories of causes of anovulation:
This classification has the advantage of being treatment orientated, i.e. once the diagnosis of anovulation has been made and its cause determined, the treatment for induction of ovulation in that particular condition will be clear. Hypothalamic-Pituitary Failure is a situation in which gonadotrophin concentrations are so low as to be completely unable to stimulate follicle development and oestrogen production from the ovaries – hypogonadotrophic-hypogonadism. Hypothalamic-pituitary dysfunction is characterized by normal oestradiol and FSH concentrations and usually presents as irregular or absent periods (oligo- or amenorrhea). Almost 90% of ovulatory disorders are due to this type of dysfunction and a large majority of these are due to polycystic ovary syndrome (PCOS). Ovarian failure is characterized by amenorrhea, very low oestrogen and high concentrations of FSH. High prolactin levels (hyperprolactinaemia) may often, but not always, present with galactorrhea (discharge of milk from the breast). Anovulation caused by hyperprolactinaemia is usually associated with prolactin concentrations more than twice the upper limit of normal. Using a simple diagnostic scheme, not only can the cause of anovulation be found with a minimum of fuss but it will dictate the starting treatment required.