Various hormones directly affect your reproductive cycle, therefore, your doctor may order numerous different infertility tests to help understand any underlying medical conditions. If any hormone is missing or elevated, then you may experience difficulties getting pregnant. The follicle stimulating hormone, or FSH, is one of these reproductive hormones. FSH is produced in the pituitary gland and stimulates follicles to grow. The follicles are what contain the egg cells in the ovaries.
If FSH levels are elevated, the ovaries may be experiencing an absence of responsive follicles. This occurs naturally at menopause. If FSH levels are too low, you experience a lack of ovulation due to a medical condition called hypothalamic anovulation.
How FSH Levels Are Tested
There are various tests that your doctor may order if infertility is suspected. A preliminary test is called ovarian reserve. This test is done to predict a female’s reproductive capability.
FSH levels are tested through a simple blood test. On day 3 of your cycle, or three days after you began your period, you will have a standard blood test done at your doctor’s office or clinic to draw blood. Results are often available the same day as the blood draw.
Results of FSH Test
An FSH test is completed on the third day of your cycle because FSH levels are most accurate in predicting ovarian reserves on this day. The blood from this test is used to determine the levels of a variety of hormones. The results indicate whether an imbalance in hormone levels may be affecting your chances of ovulating or getting pregnant. Doctors generally state that the lower the FSH levels, then the higher fertility. Normal FSH levels are under 10 mIU/ml, but anything below 15 mIU/ml is still typically considered normal. FSH levels between 15 and 25 mIU/ml are considered borderline and anything above 25 mIU/ml is abnormal.
Through the results of your FSH blood test, your doctor can suggest various infertility treatments to help you conceive. By having a baseline FSH test, your doctor is able to track how your body responds to these treatments.
What to Expect after the FSH Test
In addition to FSH test, your doctor may also order tests of your estradiol levels. This is an estrogen that is secreted by the ovaries. During ovulation, this hormone increases rapidly. Estradiol levels are another effective way to predict ovarian reserves.
Another test that your doctor may order is a clomiphene challenge test. After taking a five-day cycle of clomiphone, a fertility drug that helps induce ovulation, your doctor will order more blood work. This blood test helps determine the number and quality of eggs in your ovarian reserves. The clomiphene challenge test is typically ordered for women with a FSH measurement between 10 and 15 mIU/ml and an estradiol measurement above 65 pg/mL.
Accuracy of FSH Test Results
Various labs establish differing FSH levels as normal. You may want to talk with your medical team to determine which ranges you want to use to calculate your FSH results. FSH levels can fluctuate due to stresses, illness and environment, and there is always the chance of lab error. To best ensure accuracy of FSH results, multiple FSH tests should be taken over several months.