Inhibin B

About

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 responsiveness to treatment.