Patients often wonder about the fertilization methods used in the laboratory: is it better to have classic IVF (In Vitro Fertilization) or ICSI (IntraCytoplasmic Sperm Injection)?
Each method has specific functions. The fertility expert and the embryologist can guide you, explain and implement a complete personalized plan for you based on your needs. To select the fertilization method the main factor is sperm quality and the patient’s medical history and health.
Classic IVF is used in cases where all parameters of a semen sample (number, motility and morphology) are within normal values. This technique involves preparing the sperm sample and mixing the appropriate amount of the prepared sample with the eggs (oocytes).
The eggs and sperm then remain in the same plate in the incubator, in conditions similar to those during natural conception, in order to achieve “cooperation” between them that will lead to fertilization. This method reduces the extra handling of eggs and sperm and allows natural selection.
The fertilization success rate is about 65-70%. The rate of failed fertilization, when the sperm sample and eggs are of good quality, is low (1-2%).
The method of IntraCytoplasmic Sperm Injection is used mainly in cases of male infertility, when the number, motility and morphology of the sperm are below the reference values, in cases with a history of low or failed IVF fertilization, if the semen sample shows increased oxidative stress and increased DFI or if preimplantation genetic test (PGT-M) will be performed.
This method involves the selection of only one sperm by the embryologist, based on its morphology and motility, and injecting that sperm into the egg. The whole process is done with the help of a large magnification microscope and special microcontrollers.
The fertilization success rate by this method is about 70%. It is possible in some rare cases that fertilization may not occur even after ICSI. This means that the entry of the sperm into the egg alone is not enough for fertilization to occur. The quality at the very core of the eggs and sperm and the cooperation between them are the most important factors.
The manager of the embryology laboratory Theoni Pastroma explains:
Quite often, patients ask us ‘Why not do ICSI? Wouldn’t it be better? ‘, Especially when the number of eggs we collected is low.
I would like to point out that the main indication for ICSI is the sperm quality and patient medical history. When the values in the semen analysis are normal and the final measurements of the prepared sample on the day of the egg retrieval are at good levels, then we suggest a classic IVF fertilization. Low egg count alone is not a criterion for ICSI.
Comparative studies between classic IVF and ICSI suggest that pregnancy rates are similar regardless of the number of eggs available. ICSI has been shown to offer nothing more to IVF success when sperm has normal values. Exceptions are a history of low or failed fertilization, oxidative stress and increased DFI.
All the embryologists’ team, in collaboration with the fertility experts, will discuss with you in detail what suits your treatment and will answer any questions you may have in order to have sufficient information.
