Day 3 Inhibin B Test

If you have already had a Day 3 FSH test or an Estradiol test, you may still be interested in finding out more about your underlying fertility problems. The Day 3 Inhibin B test can help to determine the quality and quantity of your ovarian reserve.

Ovarian reserve often plays a dominant role in determining whether a not a couple will conceive. So if you are having difficulties conceiving, consult with your health care provider about the Day 3 Inhibin B test.

What is Inhibin B?

Inhibin B is a protein hormone produced by your ovaries. It works to inhibit FSH, which is responsible for helping your follicles to develop. Levels of Inhibin B decrease with age.

Inhibin B is actually secreted directly by small, developing follicles in your ovaries. During the follicular phase of ovulation, small follicles eventually develop into mature eggs, ready for fertilization. Inhibin B has a sister hormone called Inhibin A, which is also produced by the ovaries.

What is the Day 3 Inhibin B Test?

The Day 3 Inhibin B test is a simple blood test that measures the amount of Inhibin B in your blood. It is performed on Day 3 of your menstrual cycle.

The Day 3 Inhibin B Test is used in order predict ovarian reserve, including egg quality and eqq quantity. Because Inhibin B is produced directly by ovarian follicles, the amount of Inhibin B in your blood directly correlates to the number of eggs that you have in your ovaries.

Inhibin B can also predict the ability of your ovaries to produce more follicles. This suggests that the hormone can predict the success of certain ovulation-inducing drugs, like Clomid.

Inhibin B and Infertility

Inhibin B does seem to be directly related to fertility.

Low levels of Inhibin B are associated with: 

  • impaired ovulation
  • decreased success with IVF
  • lower pregnancy rates
  • increased risk of miscarriage

Who Can Benefit from the Day 3 Inhibin B Test?

Unfortunately, the Day 3 Inhibin B is not widely available. It is difficult to perform and therefore is not found in all fertility clinics.

However, a number of women can benefit from the Day 3 Inhibin Test, including:

  • women who have shown a poor response to fertility drugs
  • women with a positive CCCT
  • women with unexplained infertility
  • women over the age of 35


Table of Contents
1. Test your egg quality and quantity
2. Reading your test results
Login to comment

Post a comment