Last week we talked about HIV and AIDS and how infected people can still have children. Today we are going to talk about a complementary method of protecting the partner and the child from possible infection if the man is affected by such a disease. This is called sperm washing.

What is the purpose of seed washing?

As the word implies, it is, in a sense, about cleaning the semen. This may be necessary if the partner has a serious infectious disease. Prominent examples of such diseases are HIV, hepatitis B and C, and syphilis. They are transmitted through bodily fluids, and blood, semen and breast milk are particularly vulnerable.

For this reason, many couples use various methods of fertility treatment. These include IVF. To reduce the risk of transmission, the pathogens can be screened out. This is possible because sperm is made up of different components. There is the sperm itself, of course, but there is also the seminal fluid and other cells. The pathogens do not usually attack the sperm directly. In the case of HIV, for example, it is the cells of the immune system that are attacked. These infected cells are called 'other cells'.

It is therefore possible to filter out all the problematic cells from the sperm before IVF, so that the partner does not come into contact with the virus in the first place.

Density gradient centrifugation - What is it?

The technique used to separate the individual components of the semen is called density gradient centrifugation. It is based on centrifugation. To do this, you put the substance you want to study in liquid form into a small tube. These tubes are then put into the centrifuge. This machine is round and when you take the lid off it looks like a carousel. And that is how it works, it just spins very fast. This pushes the individual components of the liquid outwards, towards the bottom of the tube. Anyone who has been on the St Petersburg Sleigh Ride knows this. The heavier the molecules, the further down the tube they are after the ride. Centrifugation is a very common and simple technique that is used all the time in medicine, biology and chemistry.

In this particular method, centrifugation is slightly modified. The sperm sample is centrifuged in a solution whose density increases towards the bottom of the tube. This keeps the individual components at the same level as they are after centrifugation. If this step were omitted, the components would quickly mix again.

The viable motile sperm are the only components that make it through the entire density column to the bottom of the tube in the given time. From there they can be removed.

How to get started

The procedure for male fertility testing is always the same for you as a patient or for you as a couple. In general, you should abstain from sexual intercourse and masturbation in the days before the examination. Your doctor's surgery or clinic will have a room where you can give your sperm sample in peace and quiet. Your partner can often accompany you. Rarely will you be allowed to bring the sample from home. Patients often fail to store the sample correctly (temperature, etc.). This falsifies the result. This falsifies the result and helps no one.

After you have given the sample, a spermiogram is usually carried out as a matter of routine. This looks at the different components of the sperm. You can find a separate blog article about spermiograms and the WHO assessment here.

If you have indicated that you have HIV or another disease that can be transmitted this way, the sample will be centrifuged. This is done as described above. The sperm will then be collected from the bottom of the tube.

The sperm are then tested again to be sure. They are only used if the new sample has tested negative for the virus. If the centrifugation has affected their function, the sperm can be placed directly into your partner's womb. If they are still fully functional, IVF can be done. If you are HIV-positive, your partner may also be given additional pre-exposure prophylaxis before insemination to further reduce the risk. Alternatively, the new sample can be frozen and used later.

Statistically, the chance of your partner or child becoming infected after this treatment is very, very small. Of course, as with all medical treatments, there can never be a 100% guarantee.

Where can you have this test done?

The technique is particularly promoted by Spanish fertility clinics. There are several in Spain and the Czech Republic where foreign patients are accepted. It is also offered in the USA. In order to provide the necessary expertise for the treatment, an infection specialist should be present in the laboratory. In addition, many clinics do not have the necessary equipment in the laboratory to specifically test for HIV. This is why there are so few clinics in Europe offering treatment.

If you are one of the couples affected, you will unfortunately need to invest a little more money, time and effort at this stage, as you will need to organise travel in addition to the actual test. On the other hand, the method offers additional protection and safety for both mother and child. HIV and all the other diseases mentioned above are not to be taken lightly, as they can be fatal. But before you rush headlong into this, why don't you go to your local fertility clinic and get some advice? Situations like this are very individual and you need to plan your next steps.

Finally, some good news at this point: yes, it is possible. If you are HIV-positive as a woman, you can have children normally. This is provided that your treatment is monitored regularly and is working. This means that you can get pregnant, have a natural birth and breastfeed without putting your baby at risk. The same applies to men. If you want to become a father despite having HIV, you can also take this therapy. Your viral load will be monitored for two years. If it is no longer present, there is no risk of infection for the child. If the treatment is successful, there is less than a one per cent chance that the baby will be infected. IVF is not even necessary for a successful pregnancy. But if you want to be sure, you can still have IVF and have your sperm tested again beforehand.

In general, you can live relatively well with HIV in the developed world. There is no cure, but there are ways to maintain your quality of life. Even if you have to go to the doctor a few more times if you want to have a baby, modern medicine can help.