Total Posts: 11
|Posted: Thu Jan 31, 2008 03:30 pm|
For a progesteron challenge test to be positive (menstrual bleeding after progesteron administration)there must be sufficient circulating estrogen.
When there is a defect in GnRH pulse production due to various causes, there is decrease in GnRH pulse frequency or amplitude, resulting in low LH/FSH. No ovarian follicles develop. No estradiol is produced. So progesteron challenge test is negative.
Now, when there is a less severe reduction in GnRH pulse frequency or amplitude, there are low levels of LH/FSH which are sufficient to cause some follicular stimulation but insufficient to cause ovulation. So estradiol is secreted. Result is amenorrhea with positive progesteron challenge test.
Such causes are anorexia nervosa in initial stages, stress, wt loss, athletic exertion.
Total Posts: 65
|Posted: Thu Jan 31, 2008 05:33 pm|
good discussions. keep going on