At a Glance

Why Get Tested?

You may get tested as part of an infertility evaluation, along with other testing.

(Are you looking instead for Inhibin A and Inhibin B Tumor Markers used for ovarian cancer? For Inhibin A testing during pregnancy, see Maternal Serum Screening, Second Trimester.)

When To Get Tested?

When you and your partner are having trouble getting pregnant (infertility); sometimes prior to some assisted reproductive procedures, such as in-vitro fertilization

Sample Required?

A blood sample drawn from a vein

Test Preparation Needed?

None; however, follow any instructions from your health care practitioner or the lab performing the testing. If you are a woman, your blood sample may need to be drawn at a particular time during your menstrual cycle, such as on day three.

What is being tested?

Inhibin B is a hormone associated with reproduction and the development of eggs in women and sperm in men. This test measures the inhibin B level in the blood and may be used as part of an infertility evaluation.

Inhibin B is made mostly by the ovaries in females, and by the testicles in males.

  • In women, inhibin B is associated with maturation of follicles in the ovaries. The follicles are the structures that develop into mature eggs. Inhibin B rises and falls at different times during each menstrual cycle.
  • In men, inhibin B plays a role in the production of sperm in the testicles. Inhibin B levels are typically higher in men with normal fertility compared to men who do not produce an adequate number of viable sperm.

These roles allow inhibin B tests to be used as a marker of remaining fertility and ovarian function in women. Less commonly, it can be used to assess fertility in men.

Women are born with a fixed number of follicles within the ovaries that can mature to become eggs. This maturation process occurs during each of your menstrual cycles. As you age, you have fewer viable follicles and so produce fewer mature eggs. Over time, the quality of the eggs decreases as well, and they are more likely to have chromosome imbalances. Levels of inhibin B and another hormone called anti-Müllerian hormone (AMH) correlate with the number of follicles you have remaining, so they are a general indicator of remaining fertility (ovarian reserve). If you are going to have assisted reproductive procedures such as in-vitro fertilization, then inhibin B and AMH levels are related to your likely responsiveness to treatment.

Common Questions

How is the test used?

This test is not routinely ordered but may be useful in specific circumstances.

If you are a woman who is having difficulty getting pregnant (infertility), then inhibin B testing may be used along with a follicle-stimulating hormone (FSH) test to see if your ovaries are not working well. Inhibin B may also be used along with an AMH test to evaluate your fertility potential (ovarian reserve) and your likelihood of conceiving. For this use, AMH is the preferred test and inhibin B is ordered less frequently.

If you are a man, your health care practitioner may sometimes order inhibin B along with an FSH test and a semen analysis to evaluate your sperm production and fertility.

When is it ordered?

Testing may be ordered when you and your partner have been experiencing infertility. Infertility is typically diagnosed when a couple has tried to get pregnant for 12 months or more without success.

Inhibin B may sometimes be ordered for women prior to an assisted reproductive procedure, such as in-vitro fertilization, to help evaluate ovarian reserve.

What does the test result mean?

The inhibin B level normally varies depending upon sex and age. Inhibin B tests are not considered diagnostic or “stand alone” tests for infertility. They are used in conjunction with other tests and clinical findings, such as your medical history and results from a physical exam.

If you are a woman of child-bearing age and your inhibin B level is low, then your fertility potential (ovarian reserve) and your likelihood of conceiving may be reduced. This does not mean that you cannot get pregnant, it is just one indicator to be considered with other fertility factors.

If you are a man and your inhibin B level is low, then it may be affecting your sperm production. This does not mean that you are not producing an adequate number of viable sperm, it is just one indicator to be considered along with other factors, such as results from a semen analysis.

Besides inhibin B, what other tests may be done?

How long does it take for results?

Inhibin B testing is not offered by all laboratories. Your blood sample may need to be sent to a reference laboratory and it may take several days for results.

Besides infertility, is inhibin testing used for other conditions?

Yes. Inhibin testing may be used for other conditions:

Is there anything else I should know?

Your inhibin B levels will normally be low to not detectable if you are a post-menopausal woman, but inhibin B tests are not currently used to show that you have gone through menopause.

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