Increase Your Chances of Success

ISCARE clinics offer patients standard assisted reproduction processes and techniques, but also the option of using special laboratory methods which can significantly increase the chances of successful treatment.  Our physicians and embryologists will automatically recommend the most suitable course of treatment based on your results and diagnosis, but you can always talk to them about the necessity and suitability of individual methods if you wish.

Sperm Sorting Methods

Multiple factors already influence the health of sperm during their maturation, which takes 70–75 days on average. Mature sperm only live for a few days and have an increased likelihood of cell damage, called DNA breaks, towards the end of their life cycle. Their presence should ideally not exceed 15% of the sample, corresponding to the natural ageing of sperm. Higher values indicate that a proportion of sperm is already being produced with damaged DNA. These sperm can cause embryo development abnormalities, in the form of embryo arrest in the case of fertilization, or lead to spontaneous abortion in the case of natural pregnancy (or IUI).

The MACS and MFSS sperm sorting methods are intended for men with elevated sperm DNA fragmentation values – especially upwards of 30%. The proportion of sperm with DNA fragmentation can be detected using a specialised examination or the comprehensive Spermpack examination.

Magnetic-activated Cell Sorting (MACS)

Magnetically activated sorting allows sperm with damaged DNA to be filtered out from a man’s ejaculate due to their altered cell membranes. This altered membrane is able to bind to specific nanoparticles. During the subsequent sorting, these particles are trapped in the magnetic field along with the sperm to which they have bound. On the other hand, sperm without damaged DNA remain unbound and flow freely through the filter. In contrast to MFSS, this method is also suitable for men with a lower sperm concentration in the ejaculate, or for sorting thawed samples.

Microfluidic Sperm Sorting (MFSS)

This is a method that mimics the natural mechanism of sperm sorting. Unlike MACS, in MFSS sperm travel through special channels, ensuring only motile sperm pass this filtration method. These channels also filter out sperm with morphological abnormalities, including those with cell membrane changes caused by DNA fragmentation. This allows high-quality, motile sperm with intact DNA to be sorted. This method significantly increases the success rate of pregnancy, reduces the risk of miscarriage, and is suitable for IVF, ICSI, and IUI. However, it cannot be used with thawed samples.

ICSI (Intracytoplasmic Sperm Injection)

This is a micromanipulation technique during which one sperm cell is inserted into each matured egg using a very thin capillary tube. The sperm cell is selected by an embryologist under a microscope with several qualitative criteria being considered. The success rate of egg fertilisation using this technique is around 80%.

This technique can be used only in IVF and it eliminates the male infertility factor, especially low sperm motility. This technique must be employed if microsurgically sampled sperm cells (MESA/TESE) are used.

Given that ICSI significantly increases the chances of fertilisation of the highest number of eggs possible, it is also recommended for couples with cases of:

  • Failure of previous IVF treatment
  • A lower number of eggs obtained during retrieval
  • Use of frozen sperm
  • Use of donor eggs
  • Poor semen analysis results (abnormal shape, low sperm count and motility)
  • Genetic testing planned for the embryos

Activation of non-motile sperm cells before ICSI

The term asthenozoospermia denotes sperm cells with significant differences in motility, including situations when they do not move at all. If dead sperm cells are present in the ejaculate (necrozoospermia), these do not move either, which is why it is important to distinguish between these two situations. A sperm mobiliser is used so that the embryologist can distinguish dead sperm cells from living but motionless sperm cells. A mobiliser is a solution used to set the non-motile sperm cells in motion when added to a semen sample, helping the embryologist to visually distinguish them from the dead sperm cells. The living sperm cells can then be used to fertilise an egg. This technique is also used in cases of sperm obtained from testicular tissue via microsurgical sampling (MESA/TESE).

Assisted Oocyte Activation After ICSI

When an egg meets a sperm, the egg (oocyte) activation begins, which starts the fertilisation and embryonic development processes. This activation is caused by sperm factors which lead to increased calcium production in the egg. If the sperm cell does not have these factors or the egg does not react to them correctly, the process may not activate and fertilisation could fail. Assisted activation uses calcium ionophore, a solution into which the fertilised egg is transferred for approximately 15 minutes after ICSI. Afterwards, it is cleaned and put in the incubator for cultivation.

Assisted oocyte activation is suitable mainly if the ICSI technique has failed in the previous cycle or if sperm obtained from testicular tissue via microsurgical sampling (MESA/TESE) is used.

Prolonged Embryo Cultivation

In natural pregnancy, the egg is fertilised in the fallopian tube. The embryo then moves to the uterine cavity, where it can implant. This journey takes around 5 to 6 days. During this time, the embryo moves to the blastocyst stage. However, not all embryos do this successfully – some embryos stop developing during this interval for various reasons. The most common cause is a genetic defect in the embryo. Such an embryo then fails to implant and a miscarriage occurs – usually indistinguishable from normal menstruation.

In assisted reproduction via IVF, the egg is fertilised in an embryology laboratory. If the fertilisation is successful, embryologists monitor the embryo for the next three days to see whether its cells are dividing. The embryo is transferred into the uterus on the third day. However, at this moment, it is not certain whether the embryo will continue to develop and whether it will reach the blastocyst stage.

With prolonged cultivation, it is possible to monitor the embryo until the fifth or sixth day. This helps us transfer only those embryos which have reached the blastocyst stage and thus significantly increase the chances of the treatment cycle and pregnancy succeeding. The embryo is also transferred to the uterus at the same time as it would during a spontaneous conception.

Prolonged cultivation is a standard practice and is widely recommended when the remaining embryos are to be frozen (vitrified), because only embryos which have reached the blastocyst stage can be frozen. These also better tolerate being frozen and subsequently thawed.

Time-Lapse Embryo Monitoring

In cases of prolonged cultivation, embryo development is monitored manually by removing them from the incubator and studying them under a microscope. This is done on the first, third and fifth day of cultivation. Thanks to the Geri time-lapse incubator, we can continuously monitor embryo development throughout the entire cultivation in much greater detail. This is possible due to a built-in camera which records every embryo separately at regular 5-minute intervals. Therefore, the embryos do not need to be removed from the incubator, which helps to preserve the optimal conditions for their development. The resulting time-lapse video can be analysed by an embryologist to monitor the course of development and successfully detect potential anomalies during division. This helps select the most suitable embryos for embryo transfer or freezing, which increases the probability of a successful cycle. Time-lapse monitoring is recommended mainly for couples whose implantations have repeatedly failed, or couples who are interested in genetic testing for the embryos. It should also be considered by couples in which the woman is over the age of 35 or where a severe andrological factor exists.

Assisted Zona Hatching

The embryo develops under a solid coat (zona pellucida) until it reaches a certain size. The coat bursts a few days after fertilisation due to the embryo’s growth, and this allows the embryonic cells to implant into the uterine lining. This is called nidation. In some cases, the coat is too solid, which prevents it from rupturing. This means that the embryo cannot leave it and implant, which averts the pregnancy. Such a coat is usually a little thicker, which helps embryologists indicate the need for assisted hatching, but assistance can also be provided as prevention. The principle of this intervention is to disrupt the coat with a special laser and create a small opening just before the embryo is transferred into the uterus. Preventative assisted hatching should be considered mainly in cases of:

  • older women who tend to have eggs with a harder coat
  • repeated implantation failure
  • use of frozen embryos


The transfer of the embryo into the uterus (embryo transfer), and its subsequent successful implantation in the endometrium, is one of the most important steps of fertility treatment via IVF techniques. EmbryoGlue is a cultivation medium (solution) designed specifically for embryo transfer, which contains a high concentration of certain substances (hyaluronan and recombinant human albumin) that help imitate the conditions in the uterus and thus increase the adhesion of the embryo to the lining. An international study demonstrated that it increases the chances of successful pregnancy; the clinical pregnancy rate increased from 41% when regular cultivation medium was used to 49% when EmbryoGlue was used (Bontekoe et al. Adherence compounds in embryo transfer media for assisted reproductive technologies (Review). The Cochrane Collaboration 2014).

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