Asthenozoospermia is diagnosed mainly through a semen analysis, a laboratory test that measures how well sperm move. A specialist examines the percentage of sperm that swim, including those that move forward toward an egg. If the results are abnormal, repeat testing may be recommended because sperm movement can vary between samples. Medical history, physical examination, and selected additional tests help clarify the findings.
What tests are used to diagnose asthenozoospermia?
The main diagnostic test is a semen analysis, also called a sperm analysis. It measures several features of semen and sperm, including movement, number, shape, and semen volume. According to the MedlinePlus guide to semen analysis, sperm motility describes how effectively sperm move, an important factor in their ability to reach an egg.
A laboratory specialist examines a freshly collected semen sample under a microscope. The results help a fertility specialist determine whether sperm movement is lower than expected and whether other semen measurements are also abnormal. Asthenozoospermia refers specifically to reduced sperm motility; it does not automatically mean that sperm count or shape is abnormal.
How does semen analysis measure sperm movement?
During semen analysis, the laboratory assesses the proportion of sperm that are moving and how they move. Two measurements are particularly important:
- Total motility: The percentage of sperm showing movement, whether they travel forward or move without making forward progress.
- Progressive motility: The percentage of sperm that move forward purposefully, helping them travel through the female reproductive tract.
The laboratory also records the percentage of sperm that remain immotile, or do not move. These measurements provide a more useful picture than simply knowing whether sperm are moving at all.
The World Health Organization's laboratory manual for human semen examination provides standardized procedures for assessing sperm motility and other semen characteristics. Standardized testing helps laboratories produce results that can be interpreted consistently.
What sperm motility levels are considered low?
The World Health Organization's sixth edition of its semen laboratory manual, published in 2021, reports lower fifth-percentile reference values of approximately 42% for total motility and 30% for progressive motility. These values describe findings among men whose partners conceived naturally within a year; they are not strict dividing lines between fertile and infertile individuals.
A result below one of these reference values may prompt further evaluation, particularly when other semen measurements are also abnormal. A specialist interprets the full report rather than relying on one number alone. A single result cannot reliably predict whether someone will be able to conceive naturally.
Why might semen analysis need to be repeated?
Sperm measurements can change from one ejaculation to another. Temporary illness, differences in the time since the last ejaculation, sample collection problems, and laboratory handling may affect the findings. For this reason, an abnormal first result may need confirmation with another semen analysis.
The American Society for Reproductive Medicine's male infertility guideline, developed with the American Urological Association, emphasizes the importance of repeat testing when semen parameters are abnormal. The guideline notes that at least two analyses, ideally obtained about a month apart, are important to consider in this situation.
Your clinician or laboratory will advise you when to repeat the test. Comparing samples can help determine whether reduced motility is persistent or whether the first result may have reflected normal variation or collection-related factors.
How should you prepare for a semen analysis?
Following the laboratory's collection instructions helps improve the usefulness of the result. Preparation commonly includes the following steps:
- Avoid ejaculation for the period specified by the laboratory, commonly two to seven days.
- Collect the sample in the sterile container provided, usually by masturbation in a designated private room.
- Avoid saliva and ordinary lubricants, which may affect sperm movement.
- Collect the entire ejaculate when possible and tell the laboratory if any portion is lost.
- If collection takes place at home, follow the laboratory's instructions for transport and delivery time.
Sperm movement can change after collection, so timely laboratory examination is important. The MedlinePlus semen analysis instructions provide further details about sample collection, abstinence, and handling. Always follow the specific instructions given by the testing facility.
What happens after an abnormal motility result?
If testing repeatedly shows reduced sperm motility, a urologist or fertility specialist may review the findings alongside a reproductive and medical history and a physical examination. The assessment may cover previous fertility, recent illnesses, infections, past surgery or injury, medications, and other factors relevant to reproductive health.
The examination may include an assessment of the testes and reproductive structures. Additional tests are selected according to the clinical findings rather than ordered automatically for everyone.
When are hormone tests needed?
Blood tests measuring reproductive hormones, such as follicle-stimulating hormone (FSH) and testosterone, may be appropriate when the history, examination, or semen results suggest a hormonal problem. These tests do not measure sperm movement directly; they help investigate selected possible causes of male reproductive dysfunction.
Are other laboratory tests necessary?
Further testing may be considered when the semen analysis or clinical assessment raises a specific concern. For example, if white blood cells are elevated in semen, additional evaluation may be needed to determine whether inflammation or infection is present. Specialized sperm tests are not routinely required for every person with reduced motility.
The American Urological Association's male infertility guideline, amended in 2024, recommends interpreting semen measurements together and using the clinical assessment to guide further investigation. Testing is tailored to the individual rather than based on motility alone.
Can asthenozoospermia be diagnosed from symptoms?
Reduced sperm motility usually cannot be identified by looking at semen or by noticing how ejaculation feels. It may be discovered during fertility investigations when pregnancy has not occurred as expected. Some people have no noticeable symptoms, while a separate medical condition may cause symptoms that prompt an examination.
For this reason, appearance, sexual performance, and the presence or absence of other symptoms cannot establish whether sperm movement is normal. A laboratory semen analysis is needed to assess motility.
When should you see a fertility specialist?
Consider arranging an evaluation if you have been trying to conceive for 12 months without success, or sooner when a clinician recommends it because of relevant medical history or known reproductive concerns. If a semen analysis reports reduced motility, a urologist specializing in male fertility or a reproductive medicine specialist can explain the findings and decide whether repeat or additional testing is appropriate.
Diagnosis is the first step in understanding the result. The combination of semen measurements, repeat testing when indicated, and an individualized clinical assessment provides a more reliable basis for decisions than a single motility figure.