A GROUNDBREAKING method of IVF that uses MAGNETS to separate healthy sperm could increase pregnancy success rates by 10 per cent, according to experts.


MACS – magnetic-activated cell sorting — uses biodegradable magnetic nanoparticles that stick to ageing or damaged sperm that would probably die before fertilisation. The laboratory sample is then put in a tube where sperm is passed by gravity through a magnetic field. As it rises, defective sperm coated with the antibody is caught and removed, while the remainder goes through unharmed and without obstruction. Doctors treating women through IVF can then use only the more healthy sperm for egg fertilisation, increasing the chances of pregnancy.

Experts at IVF Cube in Prague say they are highly encouraged by the MACS technique

The world-leading IVF treatment centre is one of the first to use it, and two women have already become pregnant after treatment, with another eight set to start. Dr Hana Visnova, IVF Cube’s medical director, admitted MACS was still in its early stages in the field of IVF. But from her work and research, she believes it could become a highly effective new treatment method.

She said:

We are very encouraged by the fact that the first two patients to undergo this treatment at our clinic, have been confirmed as being pregnant. Other women being treated by us have started MACS, but it is still too soon to know how successful it will be. Only a few clinics use it, it is still a very new method, and so it is impossible to be able to collate more accurate data about it. But from my personal experience of it, through research and from results at IVF Cube, I believe it to be a potentially highly important new method of IVF.

Dr Visnova added:

I am confident that it can deliver between a five and ten per cent improved chance of bringing about a successful pregnancy. IVF Cube already enjoys a high rate of success, but an increase of that amount is significant. Of course, much depends on the particular sample of sperm and circumstances of the patient, but our results so far are very encouraging.

Maintaining the genetic integrity of sperm is vital to normal embryo development, and a high level of DNA fragmentation can affect embryo development and often lead to miscarriage. Selectively removing defective sperm which are otherwise indistinguishable is believed to improve the likelihood of pregnancy through assisted reproductive treatments. Sperm in a small tube has the marker protein Annexin V added and allowed to mix for about 15 minutes at room temperature. It is then held in place between magnets, which causes a block to poor quality sperm passing upwards due to gravity. Healthy sperm passes through the magnetic field and is collected for use in the artificial insemination process.


Men who are infertile and have a high level of DNA fragmentation in their sperm, are likely to benefit, as are women who have had repeated miscarriages with an unidentified cause. Women who have had at least one previous treatment cycle or who have poor embryo quality which is not attributable to their eggs, may also be treated. Although the technique has been in use for almost three decades, mainly in clinical immunology and haematology, it has only recently been applied to IVF. One benefit of MACS is that it can be combined with additional and better proven techniques such as IMSI or PICSI. PICSI is a technique during which natural sperm selection of the matured sperm only is imitated. It works by testing the ability of the sperm to attach to the hyaluronan, the substance contained in the surface layer of the egg, in a special petri dish.


In IMSI, individual sperm is evaluated under a highly specialised microscope, where only the morphologically optimal sperm is used for the micro manipulative fertilisation. IVF Cube was established in 2011 and has a proven record of success in treating women, including many from the UK, and has an 84 per cent success rate.


Sperm in general are highly prone to damage and fragmentation of their nuclear DNA. When this DNA becomes too fragmented or too damaged, the cell begins to die naturally. If such a sperm manages to fertilise an egg it is more likely to result abnormal development of the embryo.

The initial stage of fragmentation is hard to identify, but as sperm begins to break down, it exposes a substance called phosphatidylserine on its surface.

Normally this is contained within the cell, so can be used to differentiate between healthy and unhealthy sperm. The nanoparticles used during MACS bind to this substance, making it possible to extract the unhealthy cells using a magnetic field.

Sperm DNA damage can be caused by stress, certain chemicals, the influence of free radicals, smoking and increased testicular temperature. Age is also a factor.