High & Low FSH in Men
While a handful of hormones are responsible for fertility, follicle-stimulating hormone (FSH) is the best indicator of the testes’ ability to produce sperm, as it is responsible for jumpstarting the chain of events that leads to sperm production. FSH also maintains sperm until they are ready to be released, making it a key hormone for fertility.
Testing for FSH
If you are found to have low sperm counts during your initial fertility evaluation, your Inovi fertility specialist will order blood tests to measure FSH levels along with other important hormones like Testosterone (T), Luteinizing Hormone (LH), Thyroid Stimulating Hormone (TSH) & Thyroid Hormone (T4), and Prolactin. The levels of these hormones will help create a clearer picture of your fertility.
The normal range for FSH varies widely between labs, but studies have shown that FSH levels greater than >7.0 IU/L correspond with an increased chance of an abnormal semen analyses. For this reason, measuring FSH is especially important if your semen analysis shows a low sperm count.
It is possible that ejaculatory problems or other anatomical issues are the cause of low or absent sperm rather than endocrine function, in which case FSH, LH, TSH/T4, Testosterone and Prolactin may be normal.
Causes of High FSH Levels
High FSH levels in men typically mean that the testes are not functioning properly. When this is the case, the pituitary gland that regulates hormones in your brain goes into overdrive, producing additional FSH to support sperm production.