Low testosterone (T) can wreak havoc on your sexual health, causing you to experience a lack of libido, debilitating fatigue, and erectile dysfunction.
If your testosterone problems are due to testicular injury or damage, your chances to father children will also be affected.
Testicular injury can lead to an inability to produce viable spermatozoids, low sperm count, and infertility. Low sperm count is defined as less than 39 million sperm in a single ejaculate or less than 15 million sperm per 1 ml of semen.
Furthermore, the testosterone levels inside your testes are tightly linked to the production of semen. Even if the damage affects only the hormonal function of the testes, this can impact the quality of your sperm and lead to permanent sterility.
In this article, you will learn more about the link between testosterone levels and fertility and how threatening low T can affect your ability to father children.
Testosterone and sperm production
Testosterone is essential for normal spermatogenesis. The hormone stimulates the process of meiosis, which is a type of cell division unique for sperm cells and eggs.
According to research, lack of testosterone production inside the testicles stalls the division of progenitor cells during their development into sperm. Most of the stalled cells die and the result is low sperm count, reduced sperm motility, and poor sperm morphology.
Testosterone and sperm are made in different parts and cells of the testicles. Spermatozoids grow in tubules called seminiferous tubuli which fill up the testes, while testosterone is synthesized by cells found around the tubules called Leydig cells.
Once the Leydig cells produce testosterone, it enters the tubules where it helps the growth and development of spermatozoids.
These effects are mediated by cells found inside the seminiferous tubuli called Sertoli cells. Testosterone stimulates the adhesion and release between Sertoli cells and developing sperm, which facilitates several stages of sperm cell maturation.
Testosterone is also crucial for producing seminal fluid inside the prostate gland
The production of sperm is highly dependent on the intratesticular testosterone levels, which is why the concentration inside the testes normally is about 40 times higher than serum T levels.
Due to the high T levels inside the testicles, some amounts of it can also be found in the semen after ejaculation. Testosterone concentration in semen is about 20-30 ng/dl or 1-2 ng per one ejaculation. In comparison, normal serum T levels are 300-1000 ng/dl.
Since there is just a tiny amount of T in your semen, the serum testosterone levels cannot be affected by having an orgasm. Studies confirm that ejaculation does not affect serum T. Hormones affected by ejaculation include dopamine, which briefly decreases, and prolactin which temporarily increases.
Testosterone is crucial for male fertility, but high T does not provide additional benefits as long as its levels are within physiological ranges.
Does low T cause infertility?
Low testosterone levels do not always lead to infertility. Hormonal levels inside the testicles are always significantly higher than those measured in your serum as long as the function of the testes is not completely lost.
Low T occurs in approximately 15% of subfertile men
Some men may have clinically low serum testosterone levels and still maintain their fertility. Therefore, fertile women can still get pregnant from their partner even if he has low T.
But men with low T may find it challenging to impregnate their partner due to the adverse effects of hypogonadism on sexual health. For example, low testosterone is linked to erectile dysfunction (ED) and loss of libido, while medications for ED do not always reverse the problem.
The exact effect of low T on fertility depends on the condition’s cause. Men with low T and functional testes that still produce some amounts of testosterone tend to remain fertile, albeit their fertility is usually reduced. Those with severe testicular damage and a lack of testosterone will suffer from permanent infertility.
With that being said, men who have a low sperm count are more likely to have low T than fertile men. According to research, approximately 15% of subfertile men have low testosterone. The researchers also compared semen parameters between infertile men with low (<264 ng/ml) or normal T levels. They found that sperm count, sperm volume, and motility tend to be lower in the low T group but not significantly different.
Treatment of low T and male infertility
The best therapy for low T and male infertility depends on the causes that have led to these conditions and whether the patient desires to remain fertile if possible.
Administering exogenous testosterone is the most effective way to restore the hormonal balance in men with low T and cope with the debilitating symptoms of the condition.
Yet, testosterone replacement therapy (TRT) cannot restore the levels of T inside the testicles, and therefore it will not make you fertile again.
In fact, TRT increases your serum T levels which triggers negative feedback. Your pituitary gland detects that serum T levels are already high and ceases to stimulate your testicles.
Without that stimulus, the testes no longer produce testosterone and sperm. Thus, most men will not remain fertile during TRT.
Preserving fertility is only possible in men who develop hypogonadism due to pituitary problems and still have functional testes.
In such cases, hypogonadism occurs because the gland no longer releases hormones to stimulate the production of testosterone and semen in the testes. Lack of hormonal stimulus leads to low T, secondary hypogonadism, and infertility.
If you have secondary hypogonadism and you wish to remain fertile, your doctor may prescribe you therapy with human chorionic gonadotropin (hCG).
hCG can stimulate the Leydig cells in your testes to produce testosterone similar to the pituitary hormones.
Studies report that men with secondary hypogonadism can successfully restore their T levels and fertility when taking hCG therapy. During the course of the treatment, 38 out of 75 men became fathers, only 5 of whom via assisted reproduction.
How to treat male infertility
Depending on the cause of infertility, managing the condition may also require surgery or treatment with other medications. In some cases, normal fertility cannot be restored and assisted reproductive technologies are the only option.
Certain lifestyle factors can influence your fertility as well. Scientific reviews reveal that the main factors associated with infertility are obesity, tobacco smoking, alcohol abuse, drug use, and psychological stress.
If you are exposed to any of these factors, changing your lifestyle may significantly improve your sperm count and fertility.
Can testosterone treatment make you sterile?
TRT is the best option for treating hypogonadism in men who do not desire to remain fertile. That’s because testosterone therapy is the most effective method to manage the debilitating symptoms of low T, and you like to experience improvements within the first month of your treatment.
On average, it will take 3 months until TRT completely suppresses your sperm production and you become sterile. Yet, there are rare cases in which patients have viable sperm cells in their semen even after 6 months of TRT.
Your physician will always discuss with you whether you plan on remaining fertile or not before starting TRT. Your decision may be influenced by your age, whether you have children, marital and family status, etc.
Furthermore, TRT doesn’t close the door for you to have a baby in the future if you still have functional testicles. The treatment causes gradual suppression of sperm count, so there is still a chance to impregnate your partner during the first 2-3 months of therapy.
Besides, discontinuing short-term TRT often leads to spontaneous recovery of spermatogenesis in previously fertile patients. According to one trial, spermatogenesis recovered to pretreatment levels within 6-8 months of discontinuing a 12-month TRT.
If you also wish to remain fertile throughout the course of your treatment, your doctor may consider adding hCG in addition to your testosterone medications. Several small trials reveal that taking 500 IU every other day during TRT is sufficient to maintain intratesticular levels and sperm production.
If you have had symptoms of low T, such as decreased libido or erectile dysfunction, TRT will also improve your complaints and help your sexual performance during intercourse.
Libido and sexual desire increase most significantly as soon as the 3rd week after starting TRT. Testosterone will also help you achieve erections easier and increase your satisfaction from sex. In addition, the therapy will also increase your energy levels which may help you last longer during sex.
Get a free consultation with our medical expert for any questions about hormone replacement therapy