Progestogen challenge test

Progestin challenge, or progesterone withdrawal test is a test used in the field of obstetrics and gynecology in order to evaluate a patient who is experiencing amenorrhea. Due to readily available assays to measure serum estradiol levels, this test is now rarely used. The test is performed by administering progesterone orally in the form of medroxyprogesterone acetate (Provera), or intramuscularly. If the patient has sufficient serum estradiol (greater than 50 pg/mL) then withdrawal bleeding should occur 2-7 days after the progestin is finished, indicating that the patient's amenorrhea is due to anovulation. However, if no bleeding occurs after progesterone withdrawal, then the patient's amenorrhea is likely to be due to either a) low serum estradiol, b) HPA dysfunction or c) a problem with the uterine outflow tract, such as cervical stenosis or uterine synechiae (Asherman's syndrome). In order to distinguish between hypoestrogenism or a uterine outflow tract problem, estrogen may be administered followed by a course of progestin in order to induce withdrawal bleeding. If the patient experiences withdrawal bleeding with the combined estrogen/progestin therapy, then the amenorrhea is likely due to low estrogen.