Advanced Female Fertility Tests - Day 3 Inhibin B Test

A day 3 inibin test is an important diagnostic tool that represents one of the advanced tests used to evaluate female fertility. This type of female fertility test is generally used when blood tests such as a day 3 FSH test and an estradiol test are inconclusive. A day 3 inhibin test is used to determine a woman’s egg quality and quantity, known as a woman’s ovarian reserve.

What is Inhibin B?

Inhibin B is a protein hormone that the ovaries produce; this hormone prevents the stimulation of follicle stimulating hormone (FSH), which plays an important role in the development of the follicles. Inhibin B levels increase with age.

Inhibin B is produced in the maturing follicles located with the ovaries that eventually develop into mature eggs. This hormone has a sister hormone that is also produced by the ovaries known as inhibin A.

Inhibin B and Fertility

Low inhibin B levels are linked to female fertility problems, including the following:

  • poor ovulation
  • low pregnancy rates
  • high risk miscarriage
  • low IVF success

This type of female infertility test is especially beneficial for women over the age of 35 and women with unexplained infertility. In addition, a day 3 inhibin B test is also beneficial for women who have not responded well to fertility drugs.

Inhibin B Test Procedure

An inhibin B test is a blood test in which a blood sample is drawn on day 3 of the menstrual cycle so as to evaluate egg quality as well as egg quality. Because inhibin B is produced directly in the ovaries, the amount of the hormone found in the blood directly corresponds to the number of eggs found in the ovaries. This test can also determine the ability of the ovaries to produce a sufficient amount of follicles as well as to establish whether certain fertility drugs like Clomid would b effective.

After a blood sample is drawn, it is send the lab for analysis. Test results are typically ready within a week.

Normal results are any value above 45 pg/mL, while anything below this amount is considered to be abnormal. If your day 3 inhibin B test results are found to be abnormal, your fertility specialist will discuss fertility treatment options with you and your partner. Treatment options for abnormal inhibin B levels include fertility drugs such as prednisone and dexamethasone, which stimulate ovulation. In addition, an egg donor may also be used for assisted reproduction methods such as in vitro fertilisation (IVF).