Changes in pituitary and ovarian hormones following injection of ultra low dose LH-RH in normal and amenorrhoeic women.

The results of the ultra low doses of synthetic LH-RH, 1.56, 3.125 and 6.25 mug, are presented in 8 normal women during the first week of the menstrual cycle and 14 patients with secondary amenorrhoea. Seven of these patients had "stress" amenorrhoea, and 7 had preceeding oligomenorrhoea. There was no significant difference between the mean basal gonadotrophin levels in the normal volunteers and those patients with secondary amenorrhoea. There was no significant difference in basal gonadotrophin levels or the response to LH-RH, between the two groups of amenorrhoea, stress and previous oligomenorrhoea. Basal FSH and oestradiol levels do not appear to influence the response to LH-RH. However, those patients with secondary amenorrhoea and a low basal LH (5 patients) had a significantly higher response to LH-RH at 1.56 and 3.125 mug than the amenorrhoeic patients with normal basal LH levels. Two patients with stress amenorrhoea and weight loss had an exaggerated response to LH-RH. The significance of this is discussed.