The oestrogen provocation test: a method of assessing the hypothalamic-pituitary axis in patients with amenorrhoea

The oestrogen feedback and gonadotrophin release in ten amenorrhoeic women were investigated, using intramuscular injection of 1 mg oestradiol benzoate. Serial estimations of serum oestradiol and gonadotrophins (LH and FSH) were made over a period of 72 h following the injection. Five patients demonstrated positive feedback release of LH to the oestrogen stimulus with elevated levels of LH significantly above baseline (P less than 0.001), which occurred between 48 and 72 h after the injection. Two of the five patients also demonstrated elevated FSH levels accompanying these LH peaks, The hypothalamic-pituitary axis was postulated to be intact in these five patients, and all ovulated on clomiphene. None of the remaining five subjects showed any increase in serum gonadotrophin levels in response to oestradiol and none ovulated on clomiphene when given a dose of up to 200 mg daily x5 days. This 'oestrogen provocation test" seems to be a useful means of evaluating the functional capacity of the hypothalamic-pituitary axis for gonadotrophin release and has proved useful in predicting responsiveness to clomiphene in amenorrhoeic women.