Estrogen provocation test: lack of correlation between LH and 17-beta-estradiol basal levels and LH peak response in hypothalamic chronic anovulation.

Estrogen provocation test was performed in 27 women with hypothalamic chronic anovulation: all patients received I mg of estradiol benzoate (EB) as a single im injection. Plasma 17-beta-estradiol (E2) levels were monitored during the test performed and then compared; no significant correlation was found between mean basal values of LH and E2 and the LH peak response (r = 0.246, P = 0.108 for LH; r = 0.124, P = 0.278 for E2). These data seem to indicate that basal LH values reflect the tonic secretion but not the hypothalamic responsiveness to the estrogen positive feedback; moreover, this latter seems not be influenced by the endogenous E2 levels.