No. Teratozoospermia means that a semen test found a higher-than-expected share of sperm with an unusual shape. It can make conception harder in some situations, but the result alone does not prove that someone is infertile. Many other factors matter, including how many sperm are present, how well they move, the specific shape changes, and the reproductive health of both partners.
A report of teratozoospermia can be worrying when you are trying to have a baby. However, sperm shape is only one part of a fertility assessment. Some people with abnormal sperm morphology can conceive naturally, while others may need further testing or fertility treatment. Understanding what the result measures, whether other semen parameters are affected, and how long pregnancy has been taking to occur can help put the finding into perspective.
What does teratozoospermia mean?
Teratozoospermia, also called teratospermia, describes semen in which a higher proportion of sperm have an unusual shape. Sperm morphology is the medical term for sperm size and structure. A typical sperm has a head containing genetic material, a middle section that supports its movement, and a tail that helps it swim. Changes in the head, middle section, or tail may affect how sperm function.
According to Cleveland Clinic, examples of unusual sperm shapes include sperm with an abnormally shaped head, an extra head, or a bent or coiled tail. A laboratory examines a semen sample under a microscope and reports the proportion of sperm that meet its criteria for normal morphology. A finding of teratozoospermia describes this laboratory observation; it does not automatically establish infertility.
Can you get pregnant naturally with teratozoospermia?
Yes, natural conception may still be possible. An abnormal morphology result does not necessarily mean that every sperm is unable to fertilize an egg. The effect on fertility depends on the nature of the abnormalities and the overall reproductive picture. Some people have a lower proportion of normally shaped sperm while their sperm count and movement remain within expected limits.
The joint American Urological Association and American Society for Reproductive Medicine (AUA/ASRM) guideline explains that individual semen measurements, including morphology, are generally not reliable enough on their own to predict fertility or establish infertility. The likelihood of infertility may be higher when several significant semen abnormalities occur together. The guideline also recognizes that certain uncommon forms of teratozoospermia, such as complete globozoospermia, can cause serious fertilization problems. These specific conditions should not be confused with every report of abnormal sperm shape. Read the AUA/ASRM guideline.
How should sperm morphology results be interpreted?
A semen analysis measures several features of sperm and semen rather than examining shape alone. These commonly include sperm concentration, total sperm number, movement, semen volume, and morphology. The findings provide different pieces of information about reproductive function, but no single measurement can describe every aspect of a person's fertility.
MedlinePlus, a service of the U.S. National Library of Medicine, explains that semen analysis helps assess sperm quantity and quality. An abnormal result does not mean that someone is permanently infertile. Morphology percentages and reference values must also be understood in the context of the laboratory's methods and the other test findings. A healthcare professional can explain what the particular report may mean rather than relying on one number in isolation.
Does the percentage of normally shaped sperm determine fertility?
No. A morphology percentage describes the proportion of sperm classified as normally shaped under the laboratory's assessment criteria. It does not directly show whether a person will or will not conceive. Laboratory methods and reference values matter, and even a result within a laboratory's expected range cannot guarantee pregnancy. Equally, a result below that range does not rule out natural conception.
The specific pattern of abnormalities can also matter. A general finding that many sperm have unusual shapes is different from a report describing a particular, uncommon sperm disorder. If the laboratory identifies a named pattern or the report is difficult to understand, a clinician experienced in male reproductive health can explain whether it changes the assessment or the next steps.
Should an abnormal sperm morphology result be repeated?
A repeat semen analysis may be recommended because semen measurements can vary between samples. Collection conditions, the time between samples, and the laboratory's testing procedures can affect how results are interpreted. Repeating the test may help show whether an abnormal finding persists or whether the initial result was not representative of the person's usual semen measurements.
The National Institute for Health and Care Excellence (NICE) recommends a confirmatory semen analysis when the initial test is abnormal, ideally around three months after the first test. Earlier repeat testing may be appropriate when there is a major sperm deficiency, such as an extremely low sperm count or no sperm detected. The timing should follow the clinician's assessment and the applicable guidance. See the NICE fertility assessment guidance.
What happens if teratozoospermia is found during a fertility evaluation?
The next step is usually to consider the semen analysis alongside the reproductive history and other relevant findings. Depending on the situation, a clinician may review previous test results, medications, medical history, and factors that could affect sperm production. A physical examination or additional tests may be appropriate if the results or history suggest an underlying problem.
Fertility is also a shared consideration when pregnancy is being pursued with a partner. The AUA/ASRM guideline recommends assessing both partners rather than focusing exclusively on the sperm result. Factors such as the partner's age, ovulation, reproductive health, and how long the couple has been trying to conceive can influence the evaluation and the options discussed.
The American Society for Reproductive Medicine recommends starting an infertility evaluation after 12 months of trying when the person who would carry the pregnancy is younger than 35, and after six months when that person is 35 or older. Evaluation may be appropriate sooner when there is a known fertility concern; a more immediate assessment may be warranted after age 40. These timeframes guide the overall fertility evaluation and do not mean that an abnormal morphology result alone establishes infertility. Review ASRM's fertility evaluation guidance.
Does teratozoospermia mean you will need IVF or ICSI?
No. An abnormal morphology result alone does not automatically mean that assisted reproduction is necessary. Depending on the full assessment, natural conception may remain an option, or a fertility specialist may discuss treatments such as intrauterine insemination (IUI), in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI). The choice depends on the combined fertility findings, the cause of any identified problem, and the circumstances and preferences of the people involved.
A 2025 expert review from the French BLEFCO group, available through the U.S. National Library of Medicine's PubMed Central, advises against using the percentage of normally shaped sperm alone to predict outcomes or choose among assisted-reproduction methods. This reinforces the importance of looking at the overall clinical picture instead of selecting treatment solely from a morphology result.
Can sperm morphology improve?
Whether sperm morphology changes over time depends on the underlying circumstances, and an abnormal result does not identify a single cause by itself. If an evaluation finds a relevant medical condition or a potentially contributing factor, the clinician can discuss appropriate options. Repeat testing may also clarify whether the result has changed. No specific supplement, diet, or lifestyle change should be assumed to correct teratozoospermia without evidence that it is appropriate for the individual's situation.
If pregnancy has been taking longer than expected, discussing the report with a urologist or another clinician experienced in male fertility can help clarify what the findings mean and whether additional assessment is needed. The key point is that teratozoospermia can be associated with reduced fertility, but it does not automatically mean that natural conception is impossible.