What is FSH ?

FSH is an acronym which stands for Follicle Stimulating Hormone. Hormones are chemicals in your body that are made in one place and are used in another. As the name suggests, FSH is responsible for stimulating the growth of the egg-bearing follicles in your ovaries. It is one of the two gonadotropins (so called because it stimulates the gonads), the other being its partner, LH, which stands for luteinising hormone.  LH and FSH are secreted by the pituitary gland, a small pea-shaped gland below the base of your brain.   

FSH levels vary during the menstrual cycle and will peak prior to ovulation. This is why the level of FSH in your blood is best measured on Day 3 , and this is called the baseline ( basal) level. FSH blood tests are generally performed on the second or third day of your menstrual cycle, when they  provide the most accurate predictions of ovarian reserve. The FSH is often measured along with the LH level; and
estradiol .

Ovarian Reserve and Follicle Stimulating Hormone

Your ovarian reserve refers to the number of eggs that you have available for fertilization. A high ovarian reserve usually indicates a good number of viable eggs present in your ovaries. A low ovarian reserve may indicate that you have fewer available eggs. In order to test ovarian reserve, we measure your FSH level , which correlates inversely with the number of eggs that you have "on reserve" in your ovaries - your ovarian reserve. Women with a poor ovarian reserve are said to have reached their oopause. You can read more about this at www.drmalpani.com/oopause.htm. Women with poor ovarian reserve will have high FSH levels. Some women find it difficult to understand why FSH levels are high in women with poor quality eggs. Intuitively, more is better, so higher levels should mean better eggs, shouldn't it ? As one patient asked me, " If FSH stands for Follicle Stimulating Hormone, and I have high levels of FSH, then doesn't that mean that I have the ability to stimulate lots of follicles ? A high FSH should mean that I should have lots of eggs ! "

 Let’s look at the basic biology. If the ovary has many eggs, the FSH in a woman’s blood is low because the body doesn’t need to produce much FSH to induce normal ovulation. However, if the egg number is low, the body needs to work harder to produce ovulation, so it increases the amount of FSH in an effort to push the ovaries. A high FSH means the egg number is reduced, sometimes to levels so low that pregnancy is not possible.

 What is a good level? Well that depends on each individual lab. For most centers, anything over 12  mIU/ml is considered poor . In fact, some centers will not give fertility treatment to those over 12 because the odds of pregnancy become low.  

Interpreting Levels of Follicle Stimulating Hormone

A normal FSH level is usually between 3 mIU/ml – 10 mIU/ml. Levels of more than 12 mIU/ml are worrisome and suggest impaired ovarian reserve. Levels of more than 25 confirm ovarian failure and are found in menopausal women. FSH levels can also be artificially raised by ovulation inducing drugs such as clomiphene citrate ( clomid).

 Low levels of FSH ( less than 2 mIU/ml) are found in a condition called hypogonadotropic hypogonadism. Women on birth control pills as well as pregnant women also have low levels of FSH. 

The FSH level is best interpreted in conjunction with your estradiol level. Estradiol is one of the estrogens produced by the ovaries. Estradiol levels above 75 pg/ml on Day 3 may indicate a poor ovarian reserve. In some women , a high baseline estradiol level ( because of poor ovarian reserve) can artificially suppress the FSH level, so that it appears to be normal, thus misleading the doctor into believing that the ovarian reserve is normal. This is why it’s a good idea to measure the estradiol level when checking the FSH level on Day 3. If the estradiol level is high, then even if the FSH is normal, we cannot assume that ovarian reserve is normal.

 A normal FSH and estradiol level probably indicate that you have a good ovarian reserve.

Elevated FSH levels may suggest impaired ovarian reserve and may imply that you consider begin treatment right away.

High levels of FSH may indicate that you should consider using an egg donor. Your eggs may not be fertile

Treatment for a high FSH level

Traditional teaching states that there is no treatment for a high FSH level. Once the ovarian reserve is depleted, the ovary cannot grow any new eggs. However, if you have a borderline high FSH levels, there are many alternative options you can explore to try to improve your ovarian reserve.

These include:

1. yoga, to improve pelvic blood flow
2. acupuncture, to improve ovarian blood supply
3. DHEA ( dehydroepiandrosterone, 75 mg daily)
 

However, no clinical trials have been done to prove the efficacy of these interventions, so you need to understand that the results are unpredictable. However, you might want to explore these alternatives, so you have peace of mind you tried your best.

Monitor your own FSH levels

If you live in the USA, the good news is that you can now monitor your FSH levels yourself , to track your ovarian reserve ; and see how it's responding to your interventions.

 You can do this at MyMedLab !

 The Clomiphene Challenge Test

Sometimes, doctor may choose to perform a clomiphene challenge test. This is an extension of the FSH test, however, it is more sensitive. Think of it as a “stress-test” for your ovaries !

This is the way to do the test.

On Day 3 , you need to do a blood test to measure your levels of FSH,LH,PRL and TSH.

Take 100 mg clomiphene citrate ( clomid) from Day 5 - Day 9.

Repeat the blood test for FSH again on Day 10 .

If the Day 3 plus Day 10 FSH levels are more than 25, this suggests you have ovarian failure, and that donor egg IVF would be your best treatment option, if you are willing to consider this.

If it is less than 25, then consider IVF with your own eggs.

It is also necessary to consider age when undergoing fertility treatment. Age is an excellent predictor of both ovarian reserve and conception rates. Women over the age of 43 have a smaller chance of becoming pregnant than women under the age of 43, no matter what their FSH levels. This means that younger women with poor FSH levels may still want to try using their own eggs before seeking a donor.

 Other tests for ovarian reserve

 The other tests for ovarian reserve include testing for inhibin levels; and AMH levels.

Vaginal ultrasound scanning is also useful for measuring the antral follicle count.

FSH and LH levels in patients with PCOD

 We often measure both FSH and LH levels. Normally, the ratio is 1, which means the FSH level and LH level are approximately the same. In patients with polycystic ovarian disease (PCOD), this ratio is reversed; and patients with PCOD typically have a high LH level and a normal FSH level. This is called a reversal of the FSH:LH ratio; and in  patients with PCOD it is 2 or more. 

FSH as a test versus FSH as a medication

 Measuring the level of FSH in your blood is a very useful diagnostic tool . FSH is also used as a medication to help in superovulation during your IVF treatment. Brand names include Follistim and Gonal-F.

Need help in interpreting the results ?

Need help in making sense of your lab results ? Please enter your lab values and your clinical details in our Free Second Opinion form at www.drmalpani.com/malpaniform.htm and I’ll help you interpret your results !