Infertility in men facts
- Male infertility is when the man’s sperm cannot fertilize the woman’s egg, which can be due to various reasons.
- Male infertility can be the sole cause or a contributing cause to infertility when a couple’s attempts to conceive have been unsuccessful after a year of unprotected sex.
- About 15% of couples in the United States will struggle with fertility problems, and male infertility is a factor in up to 40% of those cases.
- Common causes of infertility in men include age, genetic abnormalities, sperm disorders and reproductive structural issues.
- Lifestyle factors like obesity, smoking and drug use can also contribute to infertility in men.
- Treatments for men with infertility may include medical or surgical therapy, intrauterine insemination (IUI) using his sperm or a donor’s sperm, in vitro fertilization (IVF) with ICSI (intracytoplasmic sperm injection) and other assisted reproduction treatments.
What is male infertility?
Male infertility is the inability of a man’s sperm to fertilize or reach a woman’s egg during intercourse. According to the American Society for Reproductive Medicine (ASRM), approximately 15% of couples struggle with infertility. In about 40% of those cases male factor infertility is either the sole cause or a contributing factor.
Male infertility symptoms
Often infertility in men goes unnoticed as there are no outward physical signs or symptoms. Most often, the problems stem from the quality or quantity of the man’s sperm.
Causes of infertility in men
During intercourse, a man’s sperm must travel from the vagina into the uterus and through the fallopian tube to successfully fertilize a woman’s egg.
Male infertility is generally due to:
- No sperm production.
- Not enough sperm production.
- Low sperm motility.
- Inability to deliver sperm effectively during sex.
Sperm motility (movement) and sperm morphology (shape)
The percentage of sperm that are able to move in an ejaculated sample is known as sperm motility. Normal sperm motility is defined by the World Health Organization (WHO) as more than 40% of sperm moving.
Terms associated with sperm motility
- Percentage motile is the percentage of all moving sperm.
- Forward progression indicates the percentage of moving sperm that are moving in a general forward direction.
- Total motile count (TMC) is the number of moving sperm in a single ejaculated sample.
Determining the morphology or shape of the sperm is a subjective assessment. While this is included in a semen analysis report, it is not well correlated with the potential of the sperm to be able to fertilize the egg. Treatment decisions should not be made based on morphology alone.
Sperm count and production
Normal sperm count is defined as 15 million sperm or more per milliliter of ejaculated semen. A sperm count lower than 15 million can cause problems with a man’s fertility.
Oligozoospermia, or oligospermia, is the medical term for low sperm count. There are many factors that could contribute to low sperm count, such as a hormone disorder, obesity, testosterone injections and tobacco use.
Abnormalities with a man’s testicles can also lead to a lower sperm count. Some of these abnormalities include:
- An undescended testicle can cause the testicle to not function properly.
- Swollen veins in the testicles known as varicoceles can affect the temperature regulation in the pelvic region, which can cause a decrease in sperm count.
- The absence of the vas deferens, which moves the sperm from the testicle to the urethra, can cause infertility by preventing any sperm from entering the ejaculate.
- Azoospermia refers to no sperm at all being present in the ejaculate.
Sperm production and count can also be affected by infections, anabolic steroids such as testosterone, genetic diseases like cystic fibrosis, and hormone or immune problems. Certain medical conditions such as sickle cell disease or the treatment of a seizure disorder can also harm male fertility.
If a man’s sperm is unable to reach the egg, the egg cannot be fertilized and develop into an embryo. Some factors that can impede the delivery of sperm are
- Blocked epididymis, the ducts that pass the sperm to the vas deferens.
- Erectile or ejaculatory dysfunction.
- Some lubricants that can be toxic to sperm or diminish the sperm’s ability to move (motility).
- Retrograde ejaculation, a condition that causes semen to enter the bladder instead of the urethra and out of the penis. This can be caused by diabetes and certain medications.
- Spinal cord injuries and some diseases can cause problems with ejaculation.
Infertility risk factors for men
Certain conditions or influences can increase a man’s risk for infertility, as can his age.
A man’s age
A number of factors can cause age-related male infertility.
- As men age, they experience a decline in the quality and quantity of their sperm.
- Older men see lower testosterone levels and deterioration of testicular tissue.
- Men are more likely to experience erectile dysfunction as they age.
A study from the American Journal of Gynecology found that a man’s chances for getting his partner pregnant drop 11% each year after the age of 40.
Sperm count and sperm motility rates tend to decrease with age. However, even if an older man’s sperm appears to be normal, it is still not as genetically sound as a 20-year-old man’s sperm. In fact, researchers have found that the DNA in sperm cells starts to break down around the age of 40, resulting in an increase in chromosomally abnormal sperm.
While occurrences are rare, men over the age of 40 are more likely to have children with autism or schizophrenia. Additionally, when an embryo is fertilized by abnormal sperm there is an increased risk for miscarriage.
A word of caution on low-T treatments
Testosterone is an important hormone in reproduction for both men and women. The level of this hormone gradually decreases with age, but a low testosterone level can result in depression, low sex drive, reduced muscle strength and more.
However, some treatments for low-T can negatively impact male fertility. Some forms of low-T treatments will restore a man’s testosterone to a normal level. But they also act as a form of male birth control by reducing or halting sperm production, which can make it more difficult for a man to get his partner pregnant. Long-term use of testosterone replacement can even cause permanent sterility.
Behavioral & lifestyle factors
Some behavioral or lifestyle choices can increase a man’s risk for infertility. These include certain supplements, prescription medications, excessive alcohol consumption, smoking cigarettes or chronic marijuana use.
Other lifestyle factors include:
- Having certain past or present infections.
- Taking medications for ulcers, psoriasis, depression or high blood pressure.
A man’s weight
The National Institutes of Health have published a number of studies that link obesity in men to infertility. Obesity in men can cause hormonal imbalances that can impact sperm movement and count. The disruption of mature sperm development is known as spermatogenesis.
Environmental male factors
Many researchers believe environmental causes explain an ongoing decline in male fertility.
- Being exposed to toxic substances can damage male fertility.
- Exposing the genitals to high temperatures, which can happen soaking in a hot tub or having a laptop computer on one’s lap for an extended period.
- Also problematic is in-utero exposure (before a man is born) to Diethylstilbestrol (DES), a synthetic form of estrogen, the female hormone.
- Finally, men facing the burden of a cancer diagnosis should be aware of the negative effects on fertility of medical treatments such as surgery, chemotherapy or radiation.
Genetic abnormalities that affect sperm include:
- Chromosomal translocation, which causes a part of one chromosome to attach to a different chromosome. This often causes male infertility or recurrent miscarriages in a man’s partner.
- Abnormalities or microdeletions of the Y-chromosome can cause low sperm count or azoospermia.
- Men with a disorder such as Klinefelter’s syndrome or cystic fibrosis can have problems with the flow of sperm from the testicle or low sperm production.
Fertility tests for men
The testing process for male infertility often begins as a simple conversation with a fertility specialist about health history, conditions or symptoms, and reproductive goals. This is followed by a semen analysis.
The most common test for infertility in men is a semen analysis. This test can help inform a fertility specialist on best treatment options after identifying semen abnormalities.
A semen analysis tests for:
- Motility (movement) of the sperm.
- Morphology (shape) of the sperm.
- Semen quality, including consistency, alkalinity, or acidity of the semen that could impair motility and morphology.
- The volume of sperm per ejaculated semen.
- Signs of white blood cells, which can indicate something abnormal in the semen.
A fertility doctor may also utilize additional testing such as a blood hormone analysis, ultrasound of internal organs or a biopsy to better diagnose the cause of male infertility.
Male infertility treatment
Fertility treatment options for men may vary based on age, health history and other factors. A fertility specialist will discuss options and details with each patient, and a urologist may be recommended to identify the cause and best treatment option for infertility in men.
Treatments for male infertility include:
- IUI, or intrauterine insemination, collects and injects the sperm directly into the uterus.
- In vitro fertilization (IVF) utilizes advanced techniques to fertilize an egg with sperm in a laboratory setting.
- Coupling IVF with intracytoplasmic sperm injection (ICSI) allows a single sperm to be directly injected into a single egg.
- Inserting a needle into the testicle or epididymis can extract the sperm to be used in IUI or IVF. This surgical procedure is known as testicular sperm aspiration (TESA).
- Men who cannot use their own sperm to achieve a pregnancy may use donor sperm with IVF or IUI.
- Hormone therapy may promote the production of sperm.
- Reversing a vasectomy allows sperm to be released during ejaculation.
Tips for preventing infertility in men
Avoid extreme physical activity
Intense exercise may impair sperm count, motility and morphology. It is recommended that men not exceed one hour of moderate exercise three times per week.
Eat a healthy diet
Certain foods have been shown to increase fertility in men by promoting the development of healthy sperm. Consider incorporating more antioxidant-rich foods such as avocados, pomegranates, tomatoes, and other fresh fruits and vegetables.
Overheating of the testicles is a major cause of infertility in men. Reduce the risk of overheating and infertility by avoiding frequent use of hot tubs or saunas, wearing tight clothing or sitting for long periods of time.
Do not smoke
Smoking cigarettes and cigars, and using other tobacco products, has been linked to male infertility. Chronic marijuana use has also been associated with reduced male fertility. In most cases, the nicotine and other chemicals in cigarette smoke can lead to a lower sperm count.
Do not drink to excess
A good way to prevent low sperm counts is to avoid drinking excessive amounts of alcohol. Limiting alcohol intake can also help decrease the risk of low testosterone levels and erectile dysfunction.