The clomiphene citrate challenge test is a common procedure used to determine ovarian reserve for women struggling with infertility issues. The test has been found to be over 95% accurate in determining failure rate, which makes it preferable among professionals in the field of assistive reproductive therapy.
Pharmacological Facts About Clomiphene
Clomiphene is a selective estrogen receptor modulator, whose mechanism of action is to increase gonadotropin production. This is achieved by inhibiting a negative feedback signal inside the hypothalamus. This process leads to the up-regulation, or feed-forward process, of producing more hormones.
How It Works
The Clomiphene Citrate Challenge Test begins with a patient taking a blood test on day 2 or 3 of hermenstrual cycle to measure levels of estradiol and follicle stimulating hormone (FSH). On day 5, the patient starts the diagnostic regimen by taking two pills (50 mg each) of clomiphene citrate at the same time. She would continue to take two pills every day for five days until day 9 of her menstrual period. On day 10, her FSH is measured again, completing the challenge.
Results
The expected values of the Clomiphene Citrate Challenge Test are as follows:
| Cycle Day | Estradiol/Luteinizing Hormone | FSH |
|---|---|---|
| 3 | Estradiol 65-70 | Below 10 |
| 10 | LH below 10 | Below 10 |
The test results are considered abnormal if the values for FSH on day 3 or day 10 are elevated above the normal range, or if the estradiol level is high on day 3. An abnormal result on any of these blood tests indicates an overall abnormal result, and serves as a very good predictor of a failed future pregnancy. Additionally, the reason for any unexplained infertility can be more confidently linked to a problem with her eggs and rule out other causes. On the other hand, if the results for these blood tests are normal, it does not necessarily mean that the patient is guaranteed a successful pregnancy. A successful pregnancy requires that many factors be in accordance.
Couples who have unexplained fertility would benefit from the clomiphene citrate challenge test, since the results would greatly enable them to manage their expectations for a successful pregnancy. In-vitro fertilization may or may not be a viable option depending on the results of the test. In developed or developing countries such as the Philippines, IVF success can be predicted by this measure, and a family would be able to allocate valuable resources to more viable options.