By Zaira Salvador BSc, MSc (embryologist) and Emilio Gómez Sánchez BSc, PhD (senior embryologist).
Last Update: 10/08/2018

Necrospermia or necrozoospermia is a sperm disorder characterized by the presence of dead sperm in the semen.

The reasons behind this male infertility cause are varied and the treatments sparse. For this reason, it is common for men diagnosed with necrospermia to become parents via Assisted Reproductive Technology (ART), most commonly through In Vitro Fertilization (IVF).


Necrospermia or necrozoospermia are the medical terms used when the presence of dead sperm in a man’s ejaculate is above 42%. This sperm disorder is a major cause of male infertility.

It should be noted that necrospermia is not the same as asthenospermia or asthenozoospermia, which refers to the inability for live sperm to move forward.

Under the microscope, sperm cells look like a tiny tadpole, with a round head and a slender tail that helps them “swim”. Unfortunately, for a number of reasons that we will explain below, sperms may also die.

To put it simply, when the semen has a higher amount of dead sperms than mature, normal sperms, it is likely that it is diagnosed with necrospermia. The most obvious sign is the inability for the man to get a woman pregnant.


For a complete diagnosis of necrospermia, the specialist will require you to undergo various tests, including male hormone tests, tests of sperm function, karyotype-chromosome analyses, tests of egg penetration, etc.

Amongst all of them, a semen analysis or seminogram is the basic test used to examine the different sperm parameters. Also, a hypo-osmotic swelling test can be considerably helpful to provide an accurate diagnosis of necrospermia. Continue reading to learn more about the details of each.

Semen analysis

A semen analysis, sperm test or seminogram is a test that evaluates male fertility. It is the microscopic study of a semen sample in which the condition of some parameters is studied (sperm concentration, sperm motility, and sperm morphology).

If the sample shows that more than 50% of the sperm are immotile, it might mean that they are either unviable or motionless. Necrospermia is diagnosed when they are dead, while the presence of viable-but-immotile sperm refers to a disease called asthenozoospermia.

In 2010, the World Health Organization (WHO) updated its reference values for the main semen parameters. Regarding vitality, 58% of alive sperm is the cutoff value to determine normality.

Hypo-osmotic swelling test

A hypo-osmotic swelling test is performed in order to assess sperm vitality. A viable spermatozoon has its membrane (outer layer) intact, whereas a motionless or dead spermatozoon has a perforated membrane. Therefore, a “live” cell is able to regulate the pump in and out of substances and molecules.

Sperm are introduced in a hypo-osmotic fluid and viable sperm will react to this solution swelling their body and curling their tail. Those that are unviable will not react.

A hyposmotic medium has a high amount of water and a low solute concentration. When a live sperm cell enters a high-solute concentration medium, it will absorb the water to balance the pressure.

Other vitality tests are the eosin-nigrosin and the acridine orange staining. Both are screening tests in which unviable sperm are colored while the viable remain unstained, according to the principle of membrane conservation in viable sperm.


The truth is, there are no clinical symptoms associated with necrospermia or dead sperm.

Some men with necrospermia suffer from other directly related diseases or disorders that have a series of symptoms. In these cases, the most common sigs derived from other pathologies that can lead to a necrospermia diagnosis include:

  • Spermatorrhea (excessive, involuntary ejaculation)
  • Prospermia or premature ejaculation (PE)
  • Lack of sexual desire
  • Testicular diseases: prostatitis, orchitis, epididymitis, vesiculitis, etc.
  • Orchialgia (long-term pain of the testes)
  • Perineum pain
  • Abdominal discomfort

These symptoms, however, don’t always appear and the man realizes that he has necrospermia after taking a semen test and getting medical confirmation.


Necrospermia can occur as an isolated event due to factors such as stress or the intake of certain medicines. However, there are other factors that can cause permanent necrospermia in the man, including:

  • Regular alcohol and street drug consumption
  • Unhealthy eating habits
  • Radiotherapy and chemotherapy
  • Genitourinary diseases, including urinary tract infections (UTIs)
  • Hormonal imbalances
  • Long periods of sexual abstinence

In these cases, treating necrospermia and reviving sperm is more challenging. In other words, turning to infertility treatments may be the only option to conceive.


Unfortunately, there is no cure or specific treatment for necrospermia.

If the results of the seminogram support the diagnosis of necrospermia, the test has to be repeated within three months in order to confirm such diagnosis. The presence of unviable sperm might be consequence of an isolated event, caused by temporary stressful periods, fever or even drug-induced.

If the second seminogram confirms the diagnosis, some recommendations may be given to reduce the sperm mortality rate, including leading a healthy lifestyle, with a balanced diet.

Taking dietary supplements such as vitamins and antioxidants may be helpful as well. Sperm are cells very sensitive to oxidative stress, so free radicals can severely damage or even kill them.

A diet rich in antioxidants may hinder cell death. Despite the fact that antioxidants delay cell oxidation, it should be noted that taking these supplements will not dramatically improve sperm vitality.

Finally, necrospermic men should avoid long periods of sexual abstinence, as having an elevated amount of sperms in the semen promotes their death.

Necrospermia and pregnancy

Counting the number of unviable sperm that remains in the ejaculate is a way to determine how infertile a man is. With that information, a reliable prognosis of a man’s reproductive potential can be pronounced.

Chances of getting pregnant naturally are high if a man has viable sperm in his ejaculate. However, these odds plummet if the rate of unviable sperm is above 42%. Moreover, a successful conception depends on other parameters, like count and motility.

Fertility treatments

The best option for a man with necrospermia is to visit a fertility specialist and consider undergoing in vitro fertilization (IVF). In these cases, intrauterine insemination (IUI) is not recommended, since it does not assure the process to be as successful as IVF.

ICSI encompasses the selection a sperm cell with good motility and an excellent morphological structure. Once picked, it is inserted inside the egg cell. If the sperms were found to be motionless, the specialist may use pentoxifylline to find out if they are actually live or dead.

Pentoxifylline is a sperm motility activator used in ICSI procedures when the semen sample has asthenozoospermia.


The cost of an IVF cycle may vary greatly from clinic to clinic, and depending on the particularities of each case. Nonetheless, the overall cost usually ranges between $7,000 and $8,500

Typically, the cost of a single IVF cycle does not include out-of-pocket expenses such as medications, which can add up to $4,500 or over.

In case pregnancy couldn’t be achieved using the husband’s sperm, the specialist may recommend using donor sperm. In this case, and provided that the woman has no fertility issues, turning to artificial insemination by donor (AID) may be an option to have a baby. The cost is $300-$4,000 approximately.

If you need to undergo IVF to become a mother, we recommend that you generate your Fertility Report now. In 3 simple steps, it will show you a list of clinics that fit your preferences and meet our strict quality criteria. Moreover, you will receive a report via email with useful tips to visit a fertility clinic for the first time.

FAQs from users

What causes necrospermia?

By Emilio Gómez Sánchez BSc, PhD (senior embryologist).

The term necrospermia refers to a sperm disorder where 85 percent of sperm present in the ejaculate are dead.

The factors leading to necrospermia are unclear yet, but the most common include:

  • Alcohol or street drug consumption
  • Unbalanced diet
  • Radiotherapy or chemotherapy
  • Genitourinary infections
  • Hormonal disorders

In these cases, curing necrospermia is complicated, as well as increasing sperm vitality. In short, it is likely that the affected man has to turn to assisted procreating to have children.

What does dead sperm look like?

By Zaira Salvador BSc, MSc (embryologist).

A semen sample with necrospermia has no difference with a normal sample to the naked eye. Read: What’s the Function of a Sperm Cell? – Definition & Structure.

What’s the normal range of dead sperm in a semen sample?

By Zaira Salvador BSc, MSc (embryologist).

For a semen sample to be considered normal, there should be a minimum vitality of 58%.

Can dead sperm be revived?

By Zaira Salvador BSc, MSc (embryologist).

No, it is not possible. However, with ICSI, it is possible to conceive a baby using “dead” sperms, as the sperm cell is inserted directly inside an egg. All in all, what matters is the DNA inside the sperm cell.

Can dead sperm be treated?

By Zaira Salvador BSc, MSc (embryologist).

Yes, a man can reduce the number of dead sperm in his semen by leading a healthy lifestyle, taking vitamin supplements, avoiding long periods of sexual abstinence, etc. Unfortunately, in the most severe cases, turning to Assisted Reproductive Techniques may be required to conceive a child.

Can dead sperm still fertilize?

By Zaira Salvador BSc, MSc (embryologist).

Dead sperm can make a woman pregnant only through IVF/ICSI, and provided that no other sperm parameter is affected, including sperm morphology and motility. See also: What Is ICSI or Intracytoplasmic Sperm Injection?

Does dead sperm smell like fish?

By Zaira Salvador BSc, MSc (embryologist).

There’s no direct link between bad smell odor and necrospermia. The causes of fishy smell in semen can be related to a bad diet, trichomoniasis, or prostate infections.

Is dead sperm dangerous?

By Zaira Salvador BSc, MSc (embryologist).

No. men with necrospermia can continue having full sexual intercourse without being afraid of damaging their partner or causing damage to their own genitalia.

Where do dead sperm go?

By Zaira Salvador BSc, MSc (embryologist).

Whether dead or alive, there’s a percentage of sperm that is produced and never ejaculated in all males. It just deteriorates and gets broken down over time.

Does dead sperm leave the woman’s body?

By Zaira Salvador BSc, MSc (embryologist).

Both the dead and live sperm that didn’t make it to the egg will be eliminated by means of phagocytosis, that is, the body’s own system of neutralization and elimination of substances. Read more: Sperm’s Journey to the Egg.

Suggested for you

Aside from necrospermia, there are other sperm disorders that can compromise a man’s fertility. Want to find them out? Just follow this link: Guide to Sperm Disorders.

You can learn more about the different methods to detect the presence of dead sperms in the ejaculate with this post: Methods of Sperm Vitality Assessment.

We have made several references to the seminogram or semen analysis, a basic test that is performed to evaluate the quality of a man’s semen sample in terms of sperm count, sperm morphology, sperm motility… Click here to learn more about it: What is a Semen Analysis Report?

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Authors and contributors

 Zaira Salvador
BSc, MSc
Bachelor's Degree in Biotechnology from the Polytechnic University of Valencia (UPV). Embryologist specializing in Assisted Procreation, with a Master's Degree in Biotechnology of Human Assisted Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI). More information
License: 3185-CV
 Emilio Gómez Sánchez
BSc, PhD
Senior Embryologist
Bachelor's Degree in Biology from the University of Seville. PhD in Biology from the University of Valencia. Large experience as an Embryologist Specialized in Assisted Reproduction. Currently, he is the IVF Lab Director of Tahe Fertilidad. More information
License: 14075-MU
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  1. Featured

    Hello everyone,

    We, my husband and I, have been trying to conceive for over 2 years with no luck so far, and we did a fertility test and the result of his seminogram showed a dead sperm (necrospermic) sample. I’d like to know what are our chances of getting pregnant despite this fertility problem…

    Thanks a lot!

    • Sandra FernándezBA, MA

      Dear Angelina,

      If the rate of dead sperm in the ejaculate was 50% or less, I’m afraid chances of getting pregnant naturally are quite low. Conversely, if this figure was lower than 50%, there may be still a chance to achieve pregnancy, but it will be still rather difficult. Therefore, my advice is that you consider starting a fertility treatment like IVF or ICSI.

      Best wishes

  2. Featured


    We are planning for a baby and my wife’s fertility reports are fine but in my semen report we figured out some issues as below:

    Sperm count: 312M/ml
    Volume: 3.9 ml
    pH: 7.5
    Viscosity: hyper viscous
    Round cells: 1M/ml
    Sperm vitality: 45%
    Sperm progressive: 43%
    Sperm immobile: 55%
    Sperm abnormal form: 63%

    In the conclusion of the report they mentioned that the volume and count are normal but necrozoospermia moderate (30-60%) and abnormal form is Teratozoospermie polymorphe. Presence of round cells and sperm is hyperviscous.
    Please, suggest what are the chances of conception or if a treatment is required. Many thanks.

    • Sandra FernándezBA, MA

      Hello Kumar,

      According to the WHO’s reference values, your values cannot be considered as teratospermia (you have more than 4% of normal sperm). However, necrospermia due to low vitality is present. Your chances of achieving a natural pregnancy are low for that reason, although it is not a severe case, and besides your sperm concentration is good, so you could give artificial insemination by husband (AIH) a chance.

      I hope this helps,

      All the best