An evaluation of the luteinizing hormone releasing hormone (LH-RH) test in patients with secondary amenorrhoea.

An analysis of the gonadotrophin response to an intravenous injection of LH-RH (50 mug) has been undertaken in 41 patients with secondary amenorrhoea. Thirty-five of the patients were free of any recognizable pathology to account for their amenorrhoea and apparently had a dysfunction of the hypothalamic-pituitary axis. In these patients, the gonadotrophin response to LH-RH was highly variable. There was in general a correlation between baseline plasma LH or FSH levels and their respective increments. There was no correlation, however, between basal oestrogen levels and gonadotrophin increments except in the case of those patients whose basal levels of plasma FSH were higher than those of LH and in those patients whose body weight was less than the ideal for the population. It appears that the gonadotrophin response to a single injection of LH-RH in the majority of patients with secondary amenorrhoea of unknown origin is too variable to be of use either as a diagnostic or prognostic tool.