What is the progesterone challenge test?

Answer 1

In girls with normal reproductive anatomy who have not started their period but who have begun to show signs of puberty--such as breast development and the growth of pubic hair--a progestin challenge generally is the next step in determining the cause of not ever having gotten a period. This test is also used in girls or women whose periods have ceased.

Although it might seem like the point of the progestin challenge is simply to bring on a period, it is considered to be a diagnostic test. Whether a period occurs or doesn't occur after taking the medicine provides information about the patient's current hormonal state that the doctor can then use to determine if further tests are needed.

What's involved in a progestin challenge?

In the progestin challenge test (also called a Provera challenge), a pill form of the hormone progesterone is taken by mouth once a day for five or more days to see if it triggers menstruation. If the period is going to come, it usually starts a few days after the medication is finished, although it can in fact start anywhere from a few days before the prescribed course of pills is finished to as much as two weeks after the last dose is taken.

If there is any possibility that the woman to be tested is pregnant, a pregnancy test should be done before starting the progestin challenge.

Side effects of the progestin medication

Progestins are forms of progesterone, the hormone a woman's body usually makes each month from the time of ovulation until the menstrual period. Most people who take a short course of progestin feel fine, but some have PMS-like side effects, including water retention, breast soreness, irritability, or even depression. These symptoms always resolve as soon as the drug leaves the body--typically a day or two after the medication is finished.

What do the results of the progestin challenge mean?

If a period does occur as a result of taking progestin, it means that the uterus and vagina are properly "connected" and that the uterus has been primed by the hormone estrogen. We know this because exposure to estrogen is required to build up the uterine lining before progesterone can cause the lining to be shed during menstruation.

Once it's been established that estrogen is present, it means that the ovaries contain eggs and are capable of ovulating, but they are currently not "cycling" properly. This condition is called chronic anovulation.

If no period takes place after the progestin challenge and the anatomy of the reproductive tract is normal, it means that the woman has an inadequate level of estrogen, and further tests are needed to sort out the hormonal cause for the lack of periods.