The Increasing use of testosterone replacement therapy (TRT) has tripled in the last ten years for men over the age of 40. The use of TRP has also increased in younger men.
Historically, the indications for TRP have been erectile dysfunction and fatigue, yet the question(s) remains as to if it is being used in instances where it may not be necessary, and in fact detrimental.
Many young men wish to retain their fertility or are actively trying to achieve a pregnancy when they are placed on TRT. While this may seem logical, the opposite is actually true: TRT reduces sperm production. In some males this is pronounced and thus men are rendered infertile- sometimes irreversibly so.
Testosterone Is freely available without prescription from online sources and certain herbal preparations have androgenic properties (testosterone is a hormone in the class called androgens). Therefore, for any male undergoing an evaluation for infertility where the semen analysis is abnormal, a thorough history for possible testosterone usage is required.
How does testosterone usage reduce a man’s fertility potential?
Sperm production is under the control of the hormones FSH and LH. In the testis there are two compartments. The first is located between the tubes (seminiferous tubules) where sperm are developed. The space between the tubules has cells called Leydig cells. These cells produce testosterone under the influence LH. Normal sperm production requires high levels of testosterone within the testis so giving a man testosterone seems to make sense. But that is not how mother nature designed the system. More on that in a moment. The second compartment in the testis is where the seminiferous tubules reside. The tubules have Sertoli cells which help sperm develop. The tubules have germ – cell sperm on the outer layer closely attached to the Sertoli cells. These early sperm cells split with one cell staying at the border and the other moving as it develops to the inside of the tube where it can exit the testis. This process of sperm maturation requires high intra-testicular testosterone AND the hormone FSH. Thus, both the Leydig cells and the Sertoli cells require LH and FSH to produce a normal sperm.
LH and FSH levels are controlled by the brain in what is termed the hypothalamic- pituitary- testis axis (HPT). The hypothalamus measures the testosterone level and if it is low, it sends a signal to the pituitary to tell the pituitary to release FSH and LH. This is the classic negative feedback mechanism that governs most physiologic functions. But guess what? If you take testosterone and increase the testosterone levels, the brain thinks it is overworking and shuts down the release of both LH and FSH. No FSH /LH – no sperm production.
Why has the treatment of males for “Low T” become popular?
It has become known that as some men age, their testosterone levels decline. The symptoms include decreased muscle mass, depressed mood, decreased libido, and erectile dysfunction. In 2013, approximately 2.3 million men were using TRT. The Endocrine Society and the American Urological Association both recommend treating men with symptomatic low testosterone. Yet, it is crucial that, prior to treatment, the person needs to have a proper diagnosis made. The definition of low testosterone < 300 ng/ml on two occasions. For men not currently trying to conceive but who may try in the future, a semen analysis needs to be performed. Men may want to consider freezing sperm for the unusual occurrence of permanent suppression of sperm production after the use of supplemental testosterone.
What happens to men who are on TRT and have an abnormal semen analysis?
Stopping the testosterone usually results in a return to their normal sperm production in 6 to 9 months. By 2 years, almost all males will return to their baseline sperm production if their exposure to TRT was not excessive. The use of injectable anabolic steroid and high doses of testosterone can create permanent lack of sperm production (azoospermia) which is irreversible. Some men may benefit from the use of HCG as they restore their sperm production.
Are there alternatives for treating “Low-T’ in men desiring to preserve their fertility?
Any man actively trying to achieve a pregnancy should not be addressing the “Low-T” problem. But for those not actively trying to conceive and yet suffering from the effects of “Low-T’, wishing to preserve their fertility, there are alternatives. One is the use of clomiphene citrate (Clomid), a popular fertility medication used by women to treat ovulatory problems. Clomiphene blocks the effect of androgens in the brain. The hypothalamus thinks it is not working hard enough so in response, it releases more FSH and LH. HCG (the pregnancy hormone) may be useful since the testis thinks this is LH and will stimulate the Leydig cells to produce testosterone without harming the Sertoli cells. HCG has also been shown to be effective in promoting sperm production, but the mechanism is unknown. The usual dose is 2000 IU given subcutaneously three times a week.
The bottom line:
Testosterone, in any form, is NOT a benign hormone that should be used casually for reasons that are not deemed necessary by a physician.
Men actively trying to conceive should not be placed on testosterone replacement therapy.
Men wishing to preserve the fertility while not actively trying to conceive should have two testosterone levels obtained documenting the “Low-T”. These men may benefit from either clomiphene of HCG therapy.
Men trying to conceive should consult a specialist in the treatment of infertility since conception can involve both male and female factor, the latter which can be just as, or more significant than the male factor.
Dr. John Rinehart MD, Ph.D. has been trained in both reproductive endocrinology and andrology at Brigham and Women’s Hospital of the Harvard Medical School. Dr. Rinehart is accepting new patients in Oak Lawn (708-741-7012), Bloomindale (630-221-8131) and Evanston (847-869-7777) offices.