Infertility in men at a glance
- Male infertility is an issue that prevents a man from getting his female partner pregnant after a year of regular unprotected intercourse.
- The main causes of infertility in men are low sperm concentration, poor motility (how the sperm move) and impaired delivery of the sperm to the egg.
- According to the American Society for Reproductive Medicine (ASRM) approximately 20% of couples’ infertility is due solely to male infertility and it is a contributing factor in another 30-40% of cases.
- Men in LGBTQIA relationships have the same risk of experiencing infertility as men in heterosexual relationships.
- The most common forms of male fertility testing are a physical exam, evaluation of medical history and semen analysis.
- Fertility Specialists Medical Group encourages the male partner to be tested for fertility issues anytime infertility is suspected.
- We have fertility treatments, such as intrauterine insemination (IUI), that can help overcome male infertility and treatments such as in vitro fertilization (IVF) with surgically retrieved sperm that can work around even the most severe cases of male infertility.
What is infertility in men?
Male infertility is the primary factor in 20% of infertility in couples and a contributing factor in about 30-40% of infertility cases in which both partners have infertility.
Infertility attributed to the male partner can be caused by:
- Hormonal issues
- Obstruction (inability of sperm to exit the testicle/epididymis)
- Genetic conditions affecting sperm production or obstruction
- General health and lifestyle issues
- Exposure to steroids like testosterone
- Disease or cancer
- Overexposure to environmental toxins.
Male fertility overview
A man’s reproductive system is responsible for making, storing and transporting sperm. This process is ultimately controlled by hormones, namely, testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH).
Once the testicles receive the signal to produce sperm (driven by the reproductive hormones), sperm travel from the testicles, where they are made, into the epididymis for storage. Just prior to ejaculation, the sperm moves into the vas deferens that joins the ejaculatory duct. When ejaculation occurs, the sperm mixes with fluids from the prostate and seminal vessels, creating the cloudy white substance known as semen.
Main causes of infertility in men
Often, there are no obvious physical symptoms of male infertility because the majority of such issues are in the quality or quantity of sperm produced.
Infertility in men is usually only diagnosed following a sperm analysis.
Low sperm concentration and production
Low sperm concentration and production is indicated by less than 20 million sperm per milliliter of semen. The median sperm concentration is 73 million sperm per milliliter of semen. In rare cases, the testicles may not produce sperm at all, called azoospermia.
Causes of low sperm concentration include:
- Hormone disorders
- Health and lifestyle issues such as obesity
- Frequent use of saunas or hot tubs, which can elevate core body temperature and impair sperm production and thus reduce sperm count
- Use of substances such as cocaine or marijuana may temporarily lower the number and quality of sperm
- Certain drugs, such as testosterone injections, can shut down natural hormone production, leading to decreased or no sperm production
- Smoking tobacco can often lower sperm count compared with men who do not smoke
- Excessive or prolonged emotional stress, which may interfere with hormones needed to produce sperm, lowering the sperm count
- Testicular abnormalities such as testicular inflammation/infection, varicocele (varicose vein in the scrotum), previous testicular surgeries or undescended testicle(s).
Abnormal sperm motility (movement) and morphology (shape)
Sperm must be motile (moving) to travel from the vagina, where they are usually deposited, into the uterus and out near the end of the fallopian tube to meet an egg. If fewer sperm are motile or are not moving efficiently, it is less likely that fertilization will occur.
The following sperm motility factors are diagnosed during a semen analysis.
- Percentage motile: this is the percentage of all moving sperm visualized in a microscope field from an ejaculate (semen) sample.
- Forward progression: this is an assessment of movement of the sperm, often graded using terms such as forwardly progressive, sluggish and immotile.
- Total motile count (TMC): This is a calculation of the total number of motile sperm in a single ejaculate sample. This number can be helpful in determining the utility of intrauterine insemination (IUI).
Sperm morphology refers to the shape of the sperm, most specifically the heads and tails. Sperm morphology is thought to play a role in the ability of sperm to penetrate the egg shell at the time of fertilization. Currently, the most useful assessment of morphology is a test called a Kruger strict morphology.
Impaired delivery of sperm to the egg
This affects the sperm’s ability to fertilize the egg, often because it never has a chance to get there. Causes of impaired sperm delivery include:
- Erectile dysfunction and ejaculatory dysfunction
- Some lubricants, which can be toxic to sperm or inhibit the sperm’s ability to move through the woman’s reproductive tract
- Retrograde ejaculation, which occurs when semen enters the bladder rather than emerging out of the body through the urethra (retrograde ejaculation can be a result of diabetes, bladder, prostate or urethral surgery or because of the use of certain medications)
- Blockage of the epididymis or ejaculatory ducts
- Absence of the vas deferens – even though normal sperm are produced, there is not an intact pathway to release the sperm through ejaculation
- Men with spinal cord injuries or diseases may experience dry ejaculation, in which no semen is ejaculated during an orgasm.
General health & lifestyle issues that affect male fertility
Age affects male fertility to some extent but not at the same time or at the same pace as it does in women. A man’s fertility tends to reduce after age 40 due to a variety of factors. These include decreased sperm quantity and quality, increase in erectile dysfunction, and an increase in genetic defects. Defects can lead to a higher rate of children born with single gene disorders and other conditions like autism and schizophrenia.
Excessive stress, anxiety, lack of sleep, being overweight and lack of exercise all adversely affect fertility. Infertility itself can sometimes become a long-term, discouraging problem, producing more stress. Additionally, substance abuse like alcohol or drug dependency can be associated with poor health and reduced fertility.
Health conditions affecting reproduction can be infectious, inflammatory, autoimmune diseases and genetic conditions. Examples are diabetes, thyroid disease, cystic fibrosis and Klinefelter’s syndrome.
Environmental exposure to pesticides and other chemicals
Herbicides and insecticides may cause increases in certain reproductive hormones that cause an imbalance in men’s reproductive systems. This can cause issues such as reduced sperm production and testicular cancer. Lead exposure may also cause infertility.
Cancer and cancer treatment
Cancer treatments such as chemotherapy, radiation and surgery can adversely affect a man’s fertility by damaging the reproductive organs and sperm. Testicular and prostate cancers are the most common cancers resulting in male infertility. However, cancer treatments such as radiation and chemotherapy for any type of cancer can impair sperm production, sometimes causing irreversible damage to the cells responsible for producing sperm.
Genetic abnormalities can be a cause of a low or no sperm count, or result in obstruction that affects sperm exit, making it difficult or impossible for a sperm to fertilize an egg. Couples who have a personal or family history of genetic abnormalities such as cystic fibrosis or Klinefelter’s syndrome should address these issues with a reproductive specialist before attempting to conceive.
Main categories of genetic abnormalities that affect sperm and embryos include:
- Microdeletions or abnormalities of the Y-chromosome can be a cause of low sperm concentrations (less than 5 million/ml) or azoospermia (no sperm).
- Chromosomal translocation may occur during DNA replication. One part of a chromosome may attach to a different chromosome, resulting in the embryo having too much or too little of a specific chromosome. This typically presents as an inability to conceive or as recurrent miscarriages.
- The man may have single gene disorders like cystic fibrosis that can affect the outflow tract from the testicle. Testicular or epididymal sperm extraction with in vitro fertilization (IVF) can often be used to generate a pregnancy.
Male fertility tests
The male partner should be tested for fertility issues anytime a couple is diagnosed with infertility, which is defined as no pregnancy after one year of timed intercourse when the woman is under 35, and six months when the woman is over the age of 35.
Men who have risk factors for infertility such as testicular cancer, severe trauma, chemotherapy, radiation or known genetic risks for male infertility should be tested sooner.
Common male fertility tests include:
- Physical examination and review of medical and sexual history
- Semen analysis to determine semen volume, sperm concentration (number per milliliter), motility (movement) and morphology (shape)
- Blood hormone analysis to detect variance in hormone levels
- An ultrasound of internal organs
- Biopsy to check for infection and other abnormalities.
Treatments for male infertility
A reproductive endocrinologist can develop a treatment plan to address infertility in men (and infertility in women if needed) following a thorough evaluation and infertility diagnosis.
Sometimes, a urology consult will be requested to further investigate and treat the cause of male infertility.
Common fertility treatments for male infertility include:
- Lifestyle changes, such as losing weight and quitting smoking
- IUI involves the collection and washing of sperm, and then injecting the sperm directly into the uterus; often used to treat mild male infertility.
- IVF with intracytoplasmic sperm injection (ICSI) is a procedure that involves a single sperm cell being injected into a single egg to create an embryo.
- Sperm aspiration is a surgical procedure that involves a fertility doctor inserting a needle directly into the testicle or epididymis to extract the sperm, which can then be used for IVF.
- Hormone therapy in the setting of deficiency to stimulate production of sperm in the testicle
- Vasectomy reversal to allow sperm to be released in a man’s semen during ejaculation
- Donor sperm may be needed for advanced cases of male infertility in which a man’s sperm is not viable or available; can be used in IUI or IVF.