Guide to Sperm Quality

Sperm quality refers to sperm’s ability to accomplish fertilization. Fertilization is impacted by several interconnected factors: sperm motility and sperm morphology, as well as by the health of the DNA carried by the sperm.

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:

• the sperm tail, made of protein fibers, which helps it “swim” toward the egg.
• the sperm midpiece, or body, which contains mitochondria to power the sperm’s movement.
• the sperm head, which houses the nucleus where the sperm’s precious cargo — genetic information — is stored. The head also includes the acrosomal vesicle, a tiny structure at the tip of the sperm full of enzymes that help the sperm penetrate the egg by digesting proteins and sugars on the surface of the egg.

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.

These are just a few of the most common factors affecting sperm quality:

Certain chemicals are known to impact sperm quality:

• Lead
• Pesticides
• Hydrocarbons
• PCBs, the chemical compounds found inside transformers
• Cadmium
• Diesel exhaust
• Petrochemicals
• Solvents
• Many more

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.

What you eat can affect sperm quality. The best diet for sperm quality improvement is a balanced, Mediterranean-style diet rich in:

• Fruits
• Vegetables, especially leafy greens
• Fish and other seafood
• Nuts and seeds
• Healthy fats

Moderate in:

• Soy products
• Lean protein
• Caffeine

And low in:

• Added sugars
• Processed meats
• Trans fats

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.