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Sperm analysis results explained

Donors

If you’re applying to join our donor programme, one of the first steps in the donor screening process is to provide a sperm sample for analysis. This is usually done onsite, after a short period of sexual abstinence, typically between 3 to 7 days.

We understand that undergoing a sperm analysis — and waiting for the results — can feel daunting. It’s completely normal to feel anxious. However, applying to become a donor at The London Sperm Bank also gives you the opportunity to learn more about your reproductive health in a supportive environment where discretion and compassion are always prioritised. Our scientists will talk you through your results confidentially, and counselling is available for anyone who receives unexpected or unclear findings.

In this article, we break down each part of a typical sperm analysis. We’ll explain what each measure means and what’s considered within the normal range.

What is a sperm analysis?

A sperm analysis, also known as a semen analysis or sperm test, is a common tool used to investigate male fertility by assessing sperm health. It involves a donor providing a semen sample that is then evaluated in a laboratory by looking at the sample under a microscope and through other testing.

The exact parameters assessed can vary between clinics, but typically include:

  • Semen volume
  • Sperm concentration
  • Total sperm count
  • Sperm motility
  • Sperm morphology
  • Sperm vitality
  • Semen pH

Semen ejaculate volume results explained

Semen volume refers to the total amount of fluid released during ejaculation. It’s made up of more than just sperm – in fact, sperm make up less than 5% of the total volume. The rest of the fluid comes from several glands:

  • The seminal vesicles, which provide nutrients like fructose to help sperm survive.
  • The prostate gland, which contributes zinc-rich fluid that helps stabilise sperm DNA.
  • The bulbourethral glands, which produce lubricating mucus.
  • The testes, where sperm are produced.

A healthy semen sample includes a balanced mix of these fluids to protect and support the sperm.

According to UK NHS guidance and WHO criteria, a normal semen volume is 1.4/1.5 ml or more. A result below 1.4 ml may be described as low volume (hypospermia), which can make it more difficult for sperm to reach the egg.

It’s important to note that semen volume can be temporarily affected by dehydration, frequency of ejaculation, illness, or anxiety during the collection process, so a single low-volume result doesn’t necessarily mean there is a long-term issue.

Sperm concentration results explained

Sperm concentration refers to the number of sperm present in each millilitre (ml) of semen. It’s one of the key indicators of sperm production and overall male fertility. A healthy concentration means there’s a good chance enough sperm are present in a sample to reach and fertilise an egg.

A normal sperm concentration is defined as at least 15 million sperm or more per ml of semen. A result below this is considered to be a low sperm count and is known as oligospermia. There are different degrees of oligospermia:

  • Mild oligospermia: 10 -15 million sperm per ml
  • Moderate oligospermia: 5-10 million sperm per ml
  • Severe oligospermia: 0-5 million sperm per ml

Total sperm count results explained

Total sperm count is the overall number of sperm present in the entire ejaculate sample, not just per millilitre. This figure takes into account both the concentration and the volume of semen, offering a broader view of sperm production and fertility potential.

A normal total sperm count is defined as at least 39 million sperm per ejaculate. A total count below this is considered low, even if sperm concentration per ml appears within the normal range.

Sperm motility results explained

Motility is the percentage of sperm that move. For fertilisation to occur, sperm must swim up the female reproductive tract to meet the egg. Being able to swim to their destination is essential.

There are different types of sperm motility:

  • Rapid progressive motility: This describes sperm that move swiftly and efficiently in a mostly straight line or wide arc, covering a distance equal to at least half the length of their tail each second. These are the most likely to reach and fertilise an egg.
  • Slow progressive motility: These sperm also move forward but at a slower pace. They travel in a fairly straight line or wide curve, covering roughly the length of their head per second.
  • Non-progressive motility: These sperm are moving, but not in a purposeful or forward direction. They may drift in place or move in tight, unproductive circles.
  • Total motility: This is the overall percentage of sperm showing any kind of movement, whether progressive or non-progressive.
  • Immotile sperm: This is the number of sperm with no active tail movement at all. Having some non-motile sperm is expected.

For a normal motility result, at least 40% of the sperm should be moving, and at least 32% should swim in a forward movement or large circles.

Sperm morphology results explained

Sperm morphology refers to the shape, size and structure of the sperm cells. Our scientists closely examine a sample of sperm, checking to see approximately what percentage has a normal shape. The tail, mid-section and head of a sperm cell are evaluated, as well as the measurements and proportions between each. Healthy sperm cells should have oval-shaped heads, a midpiece and a long, uncoiled tail.  At least 4% of the sperm in a sample should have a normal shape.

Sperm vitality results explained

Sperm vitality refers to the percentage of live sperm in a semen sample. It’s a measure of how many sperm are alive, regardless of whether they’re moving. Vitality can be affected by various factors, including oxidative stress, infections, fever, smoking, and environmental exposures.

References values for sperm vitality state that a normal result is 58% or more live sperm in a sample.

Seminal pH results explained

Seminal pH measures how acidic or alkaline the semen is. This is an important factor because sperm function best within a specific pH range. An environment that’s too acidic or too alkaline can reduce their mobility and lifespan. The right pH also helps protect sperm as they travel through the slightly acidic vaginal environment. The World Health Organization stipulates that the pH of a semen sample should be 7.2 or more.

What does viscosity mean in a sperm test?

Viscosity is a measure of how thick or watery a semen sample is. Normally, semen is congealed and gel-like when first ejaculated but over time (typically within 15-20 minutes) becomes more liquid to aid sperm in reaching an egg.

If semen remains too thick or becomes too watery, it can make it difficult for sperm to move and can affect the chances of egg fertilisation. Viscosity results aren’t usually given numerically but rather as normal, high or low.

Are there any other factors which are analysed in a semen analysis?

In most standard semen analyses, whether carried out through the NHS or a private clinic, the primary focus is on volume, sperm count, motility, morphology, and pH. However, additional factors may also be examined to provide a fuller picture of sperm health. Some are routinely included; others may require specific testing depending on your medical history or previous results.

Non-sperm cells

Non-sperm cells refer to cells other than sperm that are present in the ejaculate, including:

  • Immature germ cells (developing sperm)
  • Leukocytes (white blood cells, which may indicate infection or inflammation)
  • Epithelial cells (from the lining of the reproductive tract)

Non-sperm cells should make up less than 15% of the total sperm concentration. Should abnormally high levels of leukocytes be found, it’s routine for a second semen sample to be analysed three months later.

Anti-sperm antibodies

Anti-sperm antibodies are proteins produced by the immune system that mistakenly target and attach to sperm cells. These antibodies can interfere with sperm movement and function, making it more difficult for sperm to reach and fertilise an egg.

They are found in approximately 5% of samples, and a result indicating more than 50% of sperm are bound by antibodies is considered positive, with the potential to impact fertility. A result of 10% or less is considered negative.

DNA fragmentation

DNA fragmentation refers to breaks or damage in the genetic material (DNA) within the sperm. Several factors, including smoking, infections, varicocele and poor diet, can impact sperm DNA integrity.

High levels of fragmentation may reduce the chances of natural conception and increase the risk of miscarriage, even if other sperm parameters appear normal. According to the DNA fragmentation index (DFI):

  • 0–4.9% indicates excellent sperm DNA integrity
  • 5–14.9% represents adequate sperm DNA integrity
  • 15–29.9% demonstrates Elevated levels of DNA fragmentation
  • ≥30% shows severely elevated levels of DNA fragmentation

What if your semen analysis results are abnormal?

One abnormal sperm analysis result is not necessarily a sign of infertility. As so many factors can lead to poor results, such as recent illness or even stress over the test, we do allow men to repeat the test.

It is also important to note that even if you are not accepted into our donor program based on your repeat sperm analysis, it still doesn’t necessarily mean that you are infertile, because to become a sperm donor, the acceptance criteria are slightly above the normal ranges.

The decision to become a sperm donor is a truly altruistic one that has the potential to help people’s dreams come true. We truly appreciate everyone who expresses their interest in sperm donation, even if the semen analysis results mean that they cannot follow through with their intentions. This is why, at the London Sperm Bank, we offer a free semen analysis when you become a donor.

References