How Long Does Washed Sperm Survive After IUI?

Sperm washing selects the healthiest and most active sperm, giving them the best chance of reaching and fertilising the egg. Knowing how long they remain viable can help you feel reassured and set realistic expectations while you wait for results.

What is sperm washing?

Sperm washing is a specialised laboratory procedure used to prepare semen for fertility treatments such as intrauterine insemination (IUI) or in vitro fertilisation (IVF). In this process, the semen sample is carefully processed in a centrifuge to separate healthy, motile sperm from seminal fluid, dead cells, white blood cells, and other debris.

This preparation step is crucial because washed sperm are more concentrated and have a higher chance of reaching the egg for successful fertilisation. It also reduces the risk of uterine irritation or infection that could occur if unprocessed semen specimens were introduced directly into the uterus. Sperm washing is especially beneficial for couples facing male infertility or for individuals using donor sperm in their fertility journey.

Why is sperm washing done?

Sperm washing is an essential step in preparing semen for intrauterine insemination (IUI) and other fertility treatments. This process offers several key benefits:

• Safety for the uterus:

  • Raw semen contains substances like prostaglandins, proteins, and potential pathogens that can trigger cramping, allergic reactions, or even infection if placed directly into the uterus. 

  • Sperm washing removes these elements, making the insemination procedure safer and more comfortable.

• Improved sperm quality: 

  • The washing process filters out immotile or abnormal sperm and concentrates the healthiest, most motile sperm. These high‑quality sperm have a better chance of reaching the egg and fertilising it.

• Support for male infertility factors: 

  • When sperm count, motility, or shape (morphology) is lower than normal, sperm washing enhances the sample by isolating the most viable sperm for use in treatment.

• Better chances of conception:

  • By increasing the proportion of active and functional sperm, sperm washing can improve fertilisation rates and boost the likelihood of pregnancy during IUI cycles.

Differences between washed and unwashed sperm

Washed sperm is carefully processed in the lab to remove seminal fluid and keep only the healthiest, most active sperm, making it safe for direct placement into the uterus. In contrast, unwashed sperm contains seminal plasma and other components that can cause uterine cramping or even infection if used in IUI.

How long does washed sperm live after IUI?

A sperm that has been washed has a shorter life period than the one that has not been washed. This is because it lacks seminal fluid, which usually provides the sperm with protection and nutrition in the reproductive tract. After an IUI procedure, washed sperm typically survives for about 6 to 24 hours inside the uterus and fallopian tubes.

The most fertile window is usually within the first 6 to 12 hours after insemination, which is why careful timing of the IUI — ideally just before or shortly after ovulation — is essential for maximising the chances of fertilisation and pregnancy.

When does sperm potency begin to decline?

Sperm potency starts to decline soon after the washing process is completed. For the best results, IUI is usually performed within 60 to 90 minutes of washing the sperm. Beyond this period, sperm motility and viability gradually decrease, and by around 6 hours post‑washing, a significant number of sperm may lose their ability to fertilise an egg if not used.

This is why fertility clinics carefully coordinate sperm preparation and insemination to ensure the highest chances of success.

What factors affect washed sperm longevity?

Several factors can influence how long washed sperm remains viable after preparation for IUI:

• Initial sperm quality: 

  • Samples with higher baseline motility and normal morphology generally survive longer after washing.

• Sperm preparation method: 

  • Techniques like density gradient centrifugation or the swim‑up method may produce different results in sperm viability and concentration.

• Incubation conditions: 

  • Maintaining the correct temperature (around 37°C), pH balance, and using nutrient‑rich sperm media help preserve sperm health.

• Time between ejaculation and washing: 

  • Delays in processing the semen sample can reduce the quality and longevity of the washed sperm.

• Oxidative stress: 

  • The presence of reactive oxygen species (ROS) can damage sperm membranes and DNA, shortening their lifespan.

• Lifestyle and health factors: 

  • Smoking, poor diet, untreated infections, and increasing age can negatively affect sperm longevity, even after the washing process.

If you’re considering IUI or want to understand whether sperm washing could improve your chances of conception, request an appointment with us to speak to our fertility specialists today.

How does washed sperm affect IUI success?

Washed sperm is a key factor in improving the success rates of IUI. By removing seminal plasma and isolating the healthiest, most motile sperm, the process increases the concentration of high‑quality sperm placed directly into the uterus. This not only boosts the likelihood of sperm reaching the egg but also minimises adverse uterine reactions, such as cramping or inflammation, that can interfere with implantation.

Because washed sperm is immediately ready to fertilise, the procedure can be timed precisely with ovulation for optimal results. In cases of mild male factor infertility, sperm washing is especially beneficial, as it helps isolate the most functional sperm that might otherwise be lost in the raw sample.

FAQ

How long does sperm live in the body after IUI?

Washed sperm used in IUI typically survives in the female reproductive tract for about 6 to 24 hours. The highest chance of fertilisation is within the first 12 hours after insemination. Because the sperm is placed directly into the uterus, close to the fallopian tubes, it has less distance to travel — but timing the procedure around ovulation is key to improving success rates.

How long after sperm wash is IUI performed?

IUI is usually carried out within 30 to 90 minutes after the sperm washing process. Waiting longer than this can lead to a noticeable drop in sperm motility and overall viability. To maximise the chances of fertilisation, fertility clinics coordinate the procedure so that insemination happens as soon as possible after washing, ensuring the sperm remains active and healthy.

What is a good washed sperm count for IUI?

How long does unwashed sperm live?

Unwashed sperm can survive 3 to 5 days in the female reproductive tract due to the protective seminal fluid. However, it is not used for IUI because raw semen can cause uterine cramping, allergic reactions, or infections.

How long is fresh sperm good for IUI?

Fresh sperm should be washed within 30 to 60 minutes of collection to maintain motility. After washing, the processed sample is best used for IUI within 1 to 2 hours. If collected at home, keep the sample at body temperature and deliver it to the clinic within an hour.

What happens if you use unwashed sperm for IUI?

What do they do when they wash sperm for IUI?

When sperm is washed for IUI, the semen sample is processed in a laboratory to separate healthy, motile sperm from seminal fluid, dead cells, and other debris. This is usually done using techniques like centrifugation or the swim‑up method, which concentrate the best‑quality sperm. Removing seminal fluid makes the sperm safer to place directly into the uterus and increases the chances of fertilisation, as only the most active sperm are used for insemination.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.