emale Fertility Testing: Day 3 Inhibin B Test
The Day 3 Inhibin B Test is one type of female fertility test that can help diagnose fertilty problems affecting a couple’s odds of getting pregnant. More specifically, this type of fertility test can help assess ovarian reserve, which can be a sign of one type of fertility problem affecting individuals trying to conceive. But just how does this fertility testing procedure work, and how can it help diagnose female fertility problems?
What is Inhibin B?
Inhibin B is a type of hormone produced by the ovaries that works to inhibit FSH and thus the development of egg follicles. Inhibin B is actually secreted by developing egg follicles in the ovaries. As a woman ages, Inhibin B levels decrease, corresponding with ovarian reserve – a measure of egg quality as well as egg quantity.
Low levels of Inhibin B are often related to the following infertility conditions:
The Day 3 Inhibin B Test
The Day 3 Inhibin B Test is a blood test that can provide a measure of Inhibin B levels in the bloodstream. It is termed the "Day 3" test because this fertility test must be performed on the third day of the menstrual cycle. The blood sample will then be sent to a laboratory for analysis, and results will typically return within a week.
Inhibin B levels in the blood are considered to be directly related to ovarian reserve and can also provide insight into ovarian function. Predicting ovarian function is often helpful for individuals seeking infertility treatments, as this can help determine whether or not infertility drugs such as Clomid may provide an appropriate therapy to improve fertility.
Getting a Day 3 Inhibin B Fertility Test
The Day 3 Inhibin B Test is considered a more reliable fertility testing method than an FSH blood test. This is because, inhibin B levels offers more detailed insight into the potential for the ovaries to respond to certain fertility treatments.
The Day 3 Inhibin B Test may provide insight into female fertility problems in the following cases:
- women over the age of 35
- women with unexplained infertility who have a poor response to ovulation inducing medications
- women undergoing other fertility tests such as the Day 3 FSH or clomiphene challenge fertility test
- women experiencing recurrent pregnancy loss
- women with a positive clomiphene challenge test (CCCT)
- women who show poor response to fertility drugs
Fertility After Results
Normal fertility levels of Inhibin B hormones are usually 45pg/ml. Anything below 45pg/ml may indicate a fertility problem. In addition, women with subnormal Inhibin B levels undergoing IVF treatment are considered 70% less likely to conceive than women with normal Inhibin B levels and are 11 times more likely to experience a spontaneous abortion.
Nonetheless, a woman with low Inhibin B levels can still get pregnant, and typical fertility treatments include prednisone and dexamethasone to induce ovulation. In some cases, egg donations may offer a suitable fertility treatment for couples.
Speak to a health care provider such as a reproductive endocrinologist for more fertility treatment options following a Day 3 Inhibin B Test.