Follicle Stimulating Hormone (FSH) Test
This preliminary fertility test can help to assess levels of follicle stimulating hormone (FSH) in the blood. Because irregular levels of FSH are linked to female fertility problems, this female infertility test can help to diagnose the causes of fertility problems in women.
What is FSH?
FSH is a hormone that the pituitary gland produces; it helps in the regulation of egg production of the ovaries as well as helps to maintain regular menstrual cycles.
Why is A FSH Blood Test Performed?
A follicle stimulating hormone test is conducted in order to assess the causes of female infertility, including the following conditions that can contribute to fertility problems:
- ovarian reserve
- menstrual regularity, including amenorrhea (absent menstruation) and menstrual irregularities
- pituitary gland disorders, including tumors
Preparing for a Follicle Stimulating Hormone Test
Your health care provider may ask you to discontinue the use of medications that contain estrogen and/or progesterone for up to 4 weeks prior to a FSH test. Such medications include birth control pills, clomiphene, digitalis and cimetidine, which can affect the results of a follicle stimulating hormone test. Other factors that can affect a follicle stimulating hormone test result include age and excessive smoking.
You should also tell your doctor if you have undergone a medical procedure involving a radioactive tracer (such as a bone scan or thyroid scan) within the last 7 days.
In addition, it is necessary to inform your doctor of the first day of your last menstrual cycle.
FSH Blood Test Procedure
An FSH test is performed using a blood test; a sample of blood is drawn and sent to a lab for analysis, with results generally becoming available within 24 hours. However, if you are experiencing menstrual problems, you might be required to take more than one blood test in order to identify FSH irregularities, which are taken once daily for several days in a row.
Normal FSH levels for menstruating women during the follicular/luteal phase of menstruation range from 5 to 20 international units per litre (IU/L). Midcycle levels of follicle stimulating hormone peak at 30 to 50 IU/L.
High levels of FSH can indicate ovarian failure prior to the age of 40, or polycystic ovary syndrome; high FSH levels can also indicate that menopause has occurred. Alternatively, low levels of FSH indicate high stress levels, low weight, lack of egg production, as well as pituitary gland abnormalities. Low follicle stimulating hormone levels can also indicate a tumor, which interrupts the normal functioning of the pituitary gland or the hypothalamus.