Clomid Challenge Test (CCCT)

two test tubes for the Clomid challenge test

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The Clomid challenge is a type of ovarian reserve test (ORT) sometimes performed before in vitro fertilization (IVF). It is also known as a clomiphene citrate challenge test or CCCT.

Clomid challenge tests are meant to predict whether your body will respond favorably to certain fertility drugs and ovarian stimulation. Since IVF is expensive—financially, emotionally, and physically—performing this test before you begin treatment can help you avoid disappointment and save time and money.

The CCCT is only one of several ways to test ovarian reserves, however, and not all medical experts agree on whether it is the best option. Here’s why your doctor may or may not order a Clomid test, how it’s done, and what the results mean.

Why Your Doctor May Order a CCCT

The Clomid challenge test is meant to evaluate the quality and quantity of eggs in the ovaries. When your doctor talks about testing your ovarian reserves, this is what they are referring to.

Some fertility clinics perform a Clomid challenge on all patients, but most only do the test if certain criteria are met. Your doctor may order a Clomid challenge if:

  • You are over a certain age. People over age 37 are often tested, but some doctors order the test for all patients over 35.
  • Your FSH levels were high. Part of your basic fertility testing included a basal FSH test, which looks at your levels of follicle-stimulating hormone (FSH) on day three of your menstrual cycle. If your results were high (a threshold that varies among clinics), your doctor may want to do a Clomid challenge.

Your doctor may perform a challenge test during a cycle in which they are also treating you for infertility. The only difference between being treated with Clomid for anovulation and having a Clomid challenge test is that you will have more blood work and possibly an ultrasound during a challenge.

Doctors usually order a Clomid challenge before starting IVF treatment, and occasionally before intrauterine insemination (IUI) treatment.

There is a benefit to having a Clomid challenge before IVF treatment starts. If the fertility drugs used during IVF don’t stimulate your ovaries to produce enough eggs for retrieval, your cycle will be cancelled. The money (and emotional investment) spent on the treatment to that point will be lost.

The Clomid challenge test is meant to be used along with other medical information to determine whether your ovaries are likely to respond favorably before you spend time and money on treatment.

Why Your Doctor May Not Order a CCCT

Research has questioned whether the Clomid challenge is capable of detecting ovarian function and subsequent IVF treatment outcomes. While some studies have found that the CCCT can predict the likelihood of IVF success, other studies have found the test to either be inconclusive or less reliable than other ORTs.

According to a 2017 study, most OB/GYNs have stopped using the Clomid challenge test in favor of other ORTs such as FSH, anti-Mullierian hormone (AMH), and antral follicle count (AFC).

A study published in 2012 found that AFC is significantly more accurate at predicting ovarian reserves than the Clomid challenge. Additionally, an AFC test involves a transvaginal ultrasound and doesn’t require any medications.

An AMH test is a simple blood test that can be done on any day of your cycle. It is a newer test, but doctors think it may be a better predictor of ovarian reserves than other ORTs. While the Clomid challenge test requires you to take Clomid—a drug that does have side effects and risks—FSH, AFC, and AMH testing are significantly less risky.

Another issue with the Clomid challenge is that it can cause anxiety in patients, and this anxiety may not be worth the results it provides (or doesn’t provide). For these reasons, some doctors choose not to perform a Clomid challenge test.

How Is a Clomid Challenge Test Done?

The CCCT involves a blood draw on day three of your menstrual cycle. The blood will be sent to a lab to measure your FSH and estradiol levels.

On days five through nine, you will take 100mg of Clomid (clomiphene citrate). On day 10, you will have a second blood draw to measure your FSH levels again.

Some doctors also order a transvaginal ultrasound to count and measure any maturing follicles in the ovaries. 

Side Effects

You may experience the same side effects as someone taking Clomid for fertility treatment. These side effects can include:

  • Bloating
  • Breast tenderness
  • Headaches
  • Hot flashes
  • Mood swings
  • Painful ovulation

Talk to your doctor about any unusual symptoms you have during the test. Also keep in mind that if you have unprotected sex during the Clomid challenge, you can get pregnant and have higher odds of conceiving twins.

If you think you may have already passed a Clomid challenge test because you’ve taken Clomid before, check with your doctor. They may not have done the additional blood work or ultrasounds necessary for the full test at that time.

Normal Clomid Challenge Test Results

What are considered normal results for CCCT vary somewhat from lab to lab, so you will need to discuss your results with your doctor to know how they are being interpreted. In general, however, a normal FSH is below 10 IU/L on either day three or on day 10 after the five-day course of Clomid.

An elevated FSH is considered to be greater than 10 IU/L, indicating possibly diminished ovarian reserves and a predicted poor response to IVF treatment.

The higher your FSH results are during a Clomid challenge, the less likely IVF treatment will be successful. Keep in mind, though, that these test results are viewed along with the results of other ORTs such as the AFC and AMH.

Estradiol levels are also considered during a Clomid challenge. A normal day three result is below 80 pg/ml. 

Note that getting a normal result during a Clomid challenge is not a guarantee that IVF treatment will result in pregnancy or that your ovaries will respond favorably to fertility drugs. With this test, unfortunately, the only result that has meaning is a poor result.

What Happens After a Clomid Challenge Test Failure?

If your results are not good during a Clomid challenge test, your doctor will inform you that your odds of IVF treatment success are low. Most clinics will also take into consideration other ORT results along with your Clomid challenge results.

The American Society for Reproductive Medicine points out that "evidence of DOR [diminished ovarian reserve] does not necessarily equate with inability to conceive."

The next step will depend on your doctor and you. Some clinics will not offer IVF treatment to patients who fail the Clomid challenge. Using donated eggs is an option if it looks like you may not have success with traditional IVF treatment.

IVF with an egg donor has much higher success rates, even better success rates than people with good ovarian reserves going through IVF. But it is expensive, and not everyone wants to use an egg donor. Embryo donor IVF (also known as embryo adoption) is another option to consider. It is less expensive than egg donor IVF and can even be less costly than traditional IVF.

Some clinics specialize in helping patients with poor ovarian reserves. Donor IVF may be a good choice for you, but it’s best if you work with a doctor who is experienced with your particular fertility challenges.

If you want to proceed with traditional IVF knowing that your odds of success are low, some doctors may be willing to offer the treatment to you. Whether this is in your best interest, however, is a matter of debate. Getting a second opinion before investing your time, money, and emotions into treatment is a smart idea.

A Word From Verywell

Trying to conceive when you're dealing with infertility can be stressful. There are many different issues and options to sort through, and it takes time to understand what is involved with each choice.

While the Clomid challenge test (CCCT) is not used by all fertility experts, it is one tool that your doctor may use to evaluate your chances of IVF success. Talking over your options will help you and your doctor decide whether this test could be helpful for you.

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