WHO Group 1 ovulation disorders

Hypogonadotropic hypogonadal anovulation -
(Hypothalamic pituitary Failure)

- 5 to 10 % of anovulation, usually amenorrhea 
(although a range of gonadal compromise can be seen)

- Low or low-normal FSH and low serum estradiol due to decreased hypothalamic secretion of GnRH or pituitary unresponsiveness to GnRH
(Low gonadotrophins
Normal prolactin
Low oestrogen)

- Causes of hypothalamic amenorrhea include :

1. stress-or exercise-related amenorrhea, 
2. anorexia nervosa, and 
3. Kallman's syndrome (isolated gonadotropin deficiency); approximately 5 to 10 percent have hypopituitarism. 

- Reversing the lifestyle factors that contribute to the anovulation (low weight, heavy exercise) should be attempted before considering intervention with medications.