Fertility is something that many of us will take for granted: have sex, get pregnant. However, it’s not always so straightforward. Infertility is a growing problem worldwide, affecting 1 out of every 7 couples. Male-factor infertility is estimated to cause about 1 in every 3 cases. Although infertility can be due to a variety of conditions, sperm quality is one of the most important predictors of fertility.
Let’s learn more about sperm quality, including sperm morphology, motility, and DNA fragmentation, as well as what might affect your sperm quality, and how to improve sperm health.
Motility refers to the ability of the sperm to move or “swim,” which is essential for them to move through the female reproductive system and fertilize the egg.
Progressive motility is the best type of movement that can be seen in sperm quality testing. This means the sperm are moving forward in straight lines or in large circles, as opposed to in small tight circles or along erratic paths. Progressive sperm motility plays an integral role in sperm quality.
Morphology, another crucial factor for sperm quality, means the sperm’s structure or shape. Proper morphology includes:
This structure is important because it impacts a sperm’s ability to travel to, penetrate, and fertilize an egg.
Each sperm cell should contain 23 chromosomes. Chromosomes are molecules of DNA, the material that guides the growth and development of the entire human body.
Sperm cells are known as “haploid” cells, meaning they contain half the number of chromosomes in a typical human cell. The egg contains the other half. Together, they create a fully realized cell of 46 chromosomes (known as a “diploid” cell), which then divides to become all of the other cells in the body.
As you might imagine, this means the integrity of genetic material carried by sperm is essential for successful fertilization and normal embryo development. Sometimes, the DNA inside sperm can become damaged, broken, or otherwise abnormal, known as sperm DNA fragmentation. DNA fragmentation directly correlates to lower fertility in men, and is also linked to recurrent pregnancy loss (two or more consecutive miscarriages).
DNA fragmentation can be caused by many factors, including age, fever/illness, smoking, and exposure to toxins. Learn more in our guide to sperm DNA fragmentation to understand how it can affect sperm quality.
The other half of the sperm equation is sperm quantity, or sperm count/concentration. Sperm concentration refers to how densely packed those sperm are within the semen. Sperm count is the total number of sperm in a particular quantity of semen, the fluid that carries sperm out of the penis. For example, a sample may include 3 milliliters of semen with a sperm concentration of 15 million sperm per mL; that would add up to a total sperm count of 45 million.
Sperm quantity and sperm quality are separate factors. A high sperm count isn’t entirely helpful to fertility if most of those sperm are misshapen, can’t swim properly, or carry damaged DNA. But sperm quality issues and low sperm count can be caused by some of the same things, including exposure to toxins or chemotherapy, smoking, and hormone imbalance.
These are just a few of the most common factors affecting sperm quality:
As a person ages, their sperm motility decreases. According to one study, sperm motility decreases, on average, about 0.8% per year. Additionally, they’ll have lower numbers of sperm with normal morphology. Research indicates that normal sperm morphology declines 0.2–0.9% per year, resulting in a 4–18% decrease in normal morphology over a 20-year period.
The sperm of older people is more likely to have higher rates of DNA fragmentation, as well as additional genetic mutations that can lead to schizophrenia, autism, and more. The best way to prevent the issues associated with aging sperm is to freeze your sperm at a younger age. Learn more about sperm freezing options.
Certain medications, such as testosterone replacement therapy, anabolic steroids, antidepressants, chemotherapy drugs, opiates, and NSAIDs, may have an impact on sperm quality and sperm production. Whether this impact is reversible depends on the type of medication, dosage, and how long the drug is taken.
Additionally, a recent history of infection, illness, or fever can affect sperm quality. In most cases, the effect on sperm quality is temporary.
Certain chemicals are known to impact sperm quality:
Exposure to these toxins is twice as prevalent among infertile men as it is among healthy men.
While the toxins in everyday household products may also be damaging, due to long-term contact, we’re typically most concerned about those who are exposed to toxins through their occupations. Those who work in agriculture and herbicides, plastic production, and the military have, on average, worsened sperm parameters and sperm quality.
A typical semen analysis doesn’t test the genetic health of sperm. A more in-depth test is required to evaluate DNA fragmentation sperm. Legacy offers the first and only easy at-home sperm DNA fragmentation analysis.
Simple, low-intensity workouts (such as walking, biking, or jogging) have a considerable benefit for sperm quantity and sperm quality. Learn more about exercise and sperm health and physical activity’s impact on sperm quality improvement.
What you eat can affect sperm quality. The best diet for sperm quality improvement is a balanced, Mediterranean-style diet rich in:
And low in:
Having more than 5–7 drinks per week may dampen testosterone production, and negatively affects all aspects of your sperm quality including sperm count, concentration, and morphology.
Smoking can be especially bad for sperm morphology, creating genetic defects that lower sperm quality. Learn more about smoking and sperm health and how tobacco impacts sperm quality.
Chronic sleep deprivation (regularly getting less than 6–7 hours a night) may reduce testosterone levels, lower sperm count and motility, and increase levels of anti-sperm antibodies, further damaging your sperm and lowering sperm quality. Learn more about sleep and male fertility.
Examples include testosterone, anabolic steroids, SSRIs, chemotherapy drugs, opiates, NSAIDs, and any other medication that has an impact on sperm quality.
Many supplements are associated with sperm quality improvements and increased sperm count and testosterone production. Learn more about male fertility supplements and sperm quality supplements.