What are the Causes of Male Infertility?
Nearly 15 percent of couples are infertile, meaning they haven’t gotten pregnant after trying without protection for at least a year, but infertility is not just a women’s issue. Both genders can have problems that affect fertility. In fact, men can be the cause of infertility in a couple in up to 50% of cases.
Male fertility depends on a complex relationship between hormones, sperm production, and the ability of sperm to get to the egg and fertilize it. As a result, there is a spectrum of defects that can present, and these are usually characterized by the number of sperm in a semen sample. Most commonly, men present with either fewer than normal sperm (oligozoospermia) or no sperm (azoospermia) in their ejaculate. There are many health issues that can cause male fertility and impact sperm counts. Let’s dive into what some of the main causes are.
When a man does not have any sperm in his semen. This is diagnosed by performing at least two semen analyses.
There are two types of azoospermia:
A man’s testes produce sperm, but there is a "plumbing problem" that prevents the sperm from traveling out of the testes and entering the ejaculate in the urethra/penis.
This is a common cause of male infertility in which men do not produce enough sperm to have a detectable amount in their semen.
- Causes of non-obstructive azoospermia include:
- Maturation Arrest – This is a condition in which a man’s sperm can only reach a certain, incomplete stage of development.
- Sertoli-cell Only Syndrome – A condition in which a man has only Sertoli cells in the testes (cells that nurture immature sperm) and completely lacks sperm cells.
- Genetic Conditions – a number of genetic defects, many of which we do not currently test for, have been linked to male infertility. In the future, these will likely be tested for on a regular basis.
- Causes of non-obstructive azoospermia include:
- Causes of non-obstructive azoospermia or oligozoospermia include:
- Varicocele - varicose veins in the scrotum that can cause reduced sperm production in the testicles. Varicocele most often causes oligozoospermia.
- Undescended Testes - An undescended testicle stays up in the body, so it has a higher temperature. This can cause lower sperm production and a lower sperm count and quality.
- Testicular Cancer – Testicular cancer is associated with decreased sperm counts in some men, and treatment for testicular cancer can impact male fertility.
- Gonadotoxins - Radiation, chemotherapy, and some industrial chemicals that are toxic to the testes.
- Hypogonadotropic Hypogonadism – This is a problem with the pituitary gland in the brain where it does not make enough of the hormones needed to create sperm or testosterone.
- Pituitary Tumors – Can lower LH and FSH levels, which can result in low or no sperm production.
- Hypothyroidism - low thyroid hormone levels can cause poor semen quality and low sperm count.
- Exogenous Testosterone Therapy - testosterone treatment decreases sperm production by decreasing levels of follicle stimulating hormone (FSH), which is needed to stimulate sperm production, and can cause oligozoospermia or azoospermia. In most cases, the infertility caused by testosterone treatment is reversible.
- GENETIC ABNORMALITIES
A number of genetic abnormalities often cause male infertility. There are also many other genetic abnormalities that we are just beginning to understand that can lead to male infertility as well, and up to 50% of cases of infertility without a known cause can be genetic.
Some common genetic abnormalities leading to male infertility include:
- Cystic Fibrosis - Nearly all men with CF have a condition called congenital bilateral absence of the vas deferens (CBAVD), which is when part or all of both vas deferens do not develop. Although these transportation tubes are missing, the testes produce a normal amount of sperm in 90% of men with CF.
- Chromosome defects - An example is Klinefelter Syndrome (KS), in which a man has an extra sex chromosome, so they have 47, XXY instead of 46, XY.
- Kallman Syndrome – genetic condition characterizes by delayed or absent puberty and an impaired sense of smell.
- SPINAL CORD INJURIES AND/OR PELVIC TRAMA
- Injuries to the spinal cord or pelvic nerves that lead to erections and ejaculation can prevent men from having sex and getting their female partners pregnant.
There are also lifestyle factors that can influence male fertility:
- Tobacco use
- Long term narcotic use/abuse
- Drinking a moderate to excessive amount of alcohol
- Overheating the testicles regularly (using a hot tub or sauna)
- Being overweight
- Poorly treated Diabetes
For men facing fertility problems, one of the biggest challenges can be simply opening up and talking about the issue. The good news is that we can help most couples with fertility problems conceive. We have a busy infertility and men’s health program, and the only fellowship-trained andrologists in Utah. Contact us today to learn more.