A semen analysis is one of the main tests used to assess seminal health and male reproductive function. By analysing a semen sample, it examines various characteristics of sperm cells and the seminal fluid itself.

Although it is commonly associated with fertility assessment, the information it provides can be useful in different clinical situations, including the assessment of reproductive abnormalities, the investigation of inflammatory or infectious processes, follow-up after a vasectomy and the monitoring of certain treatments.

But which parameters are specifically assessed in a semen analysis, and what does each one mean?

 

What is a semen analysis?

El seminograma, también denominado espermiograma, es un análisis que estudia las características físicas y celulares del semen.

La prueba permite valorar parámetros como el volumen de la muestra, la concentración de espermatozoides, su movilidad, morfología y vitalidad, además de otras características del semen, como el pH, la viscosidad o el tiempo de licuefacción.

Estos parámetros aportan información complementaria. Por ello, el resultado de un seminograma no debe interpretarse a partir de un único valor aislado, sino considerando el conjunto de resultados y, cuando sea necesario, otros datos clínicos.

What is analysedin semen?

• Semen volume

Semen volume refers to the total amount of semen collected in the sample.

Semen consists of sperm cells and various fluids produced mainly by the accessory glands of the male reproductive system, including the prostate and seminal vesicles.

A volume outside the reference range may have different causes and should be interpreted alongside the other semen analysis parameters.

• Sperm concentration

Sperm concentration indicates how many sperm cells are present per millilitre of semen.

This parameter differs from the total sperm count in the sample, which takes both sperm concentration and semen volume into account.

A low concentration may reduce the number of sperm available to reach the egg and may therefore be associated with a lower probability of fertilisation. However, an abnormal concentration on its own cannot determine whether infertility is present.

• pH, viscosity and liquefaction

A semen analysis also examines certain physical characteristics of semen.

pH provides information about the sample’s acid-base balance. Viscosity refers to its consistency, while liquefaction is the process through which semen changes from an initially more gel-like state to a more fluid one after ejaculation.

Changes in these parameters may be related to the functioning of the accessory glands and should be assessed alongside the other results.

• Motility: how do sperm cells move?

Sperm motility describes the ability of sperm cells to move.

Not all moving sperm cells move in the same way. The analysis therefore distinguishes between different motility patterns, paying particular attention to progressive motility, in which sperm cells move forward effectively.

Motility is an important parameter because sperm cells need to move forward for fertilisation to occur.

Reduced motility may make this process more difficult, although its significance must be interpreted alongside sperm concentration, morphology and the other seminal parameters.

• Morphology: what do sperm cells look like?

Sperm morphology assesses the shape and structure of sperm cells and determines what proportion have characteristics considered normal.

This analysis examines features such as the sperm head, midpiece and tail.

Morphology is another parameter that helps assess seminal quality. A low proportion of sperm cells with normal morphology may be associated with reduced reproductive potential, but, once again, it should not be interpreted in isolation.

• Vitality: how many sperm cells are alive?

Sperm vitality indicates the percentage of live sperm cells in the sample.

This parameter is particularly important when reduced motility is observed, as an immobile sperm cell may be alive but unable to move, or it may be dead.

Assessing vitality therefore complements the information obtained from the motility analysis.

 

Can signs of inflammation be detected?

In addition to examining sperm cells, a semen analysis may, in certain circumstances, assess the presence of inflammatory cells, mainly white blood cells (leukocytes).

A high number of leukocytes in semen may be associated with inflammatory or infectious processes in the reproductive tract. Inflammation may also contribute to oxidative stress, which can affect sperm function.

The presence of leukocytes alone does not establish the cause of the process. When the results indicate it, additional tests may be needed to determine whether an infection or another cause of inflammation is present.

What does an abnormal semen analysis mean?

A result outside the reference range does not necessarily mean that infertility is present.

It is important to understand that reference values do not represent an absolute boundary between fertility and infertility. Male reproductive potential depends on multiple factors, so the results must be interpreted by considering all the parameters and each person’s clinical context.

Furthermore, seminal parameters can vary between samples. For this reason, when abnormalities are detected, a healthcare professional may recommend repeating the analysis and/or carrying out additional tests to complete the assessment.

• A semen analysis does not assess fertility alone

Although its best-known use is the assessment of male reproductive function, a semen analysis can provide information in other situations.

1. Follow-up after a vasectomy

After a vasectomy, semen analysis can be used to check for the presence or absence of sperm cells in the sample and determine whether the procedure has achieved the expected outcome.

2. Investigation of inflammatory or infectious processes

The presence of certain cells or abnormalities in seminal parameters may indicate the need to investigate possible inflammatory or infectious processes in the reproductive tract.

3. Monitoring certain treatments

Semen analysis may also be used to monitor changes in sperm parameters in certain clinical situations or during some medical treatments.

4. Disorders of the male reproductive system

Semen analysis results may form part of the assessment of certain testicular or male reproductive system disorders. For example, in patients with varicocele, semen analysis can help assess how sperm function may be affected.

How is a semen analysis interpreted?

A semen analysis must be interpreted by assessing all the parameters together.

For example, a reduced sperm concentration does not necessarily have the same significance when motility and morphology are within the expected ranges as it does when several parameters are simultaneously abnormal.

Similarly, an abnormal result alone cannot establish a diagnosis of infertility. When abnormal results are found, a healthcare professional may consider repeating the analysis or supplementing it with other tests, taking the person’s medical history and clinical situation into account.

A test thhat provides information about seminal health

A semen analysis provides an overview of different characteristics of semen and sperm cells: how many there are, how they move, what they look like, how many are alive and certain characteristics of the seminal fluid.

It is therefore an important tool in assessing male reproductive health and may form part of the investigation of different clinical situations.

If you would like to learn more about your seminal health, you can take our semen analysis test to obtain information about the main parameters assessed in the sample.