What is it and why ICSI is used? More importantly, for whom this procedure is advised?
ICSI is the intracytoplasmic sperm injection. To know more about ICSI watch 3on1 #IVFANSWERS where fertility experts explain the procedure itself and its use.
- Pilar González Dosal – Embryologist – ProcreaTec
- Dr Victoria Walker – Fertility specialist – Institut Marquès
- Dr Maria Arque – International Medical Director in Fertty International
Answer from González Dosal - Embryologist
The intracytoplasmic sperm injection (ICSI) technique involves the injection of a single sperm into each mature oocyte, using micro-manipulation equipment and under direct microscopic vision. It is a safe and standardised technique, performed by highly experienced embryologists.
After egg retrieval, we prepare the eggs by removing the cells that surround the oocyte in a process called “decumulation”. This allows us to see if the eggs are mature – mature oocytes are required for ICSI.
At the same time, we prepare the semen sample. We look for the best sperm – both in morphology and motility – before performing the microinjection. Once we have everything ready, we proceed with the technique. The entire process takes place approximately 4 hours after egg retrieval. By the following day, we’re able to check the eggs and see which ones have been fertilised.
At first, ICSI was developed to overcome severe forms of male factor infertility. Nowadays, however, it is the most used technique in assisted reproduction. ICSI is a routine clinical practice in fertility centres worldwide, used in approximately 80% of all IVF treatments performed.
ICSI enjoys a high fertilisation rate (around 80%), which, in turn, leads to more high quality embryos and higher pregnancy rates. The technique is essential when an altered male factor is present, because a low quality sperm sample will not be able to fertilise the oocyte on its own.
There are also other situations in which it is also advisable to carry out ICSI: For intsance, it is essential in cases when the sperm is obtained by testicular aspiration or a biopsy, because in most of these cases we have very few sperm cells available. ICSI is also required when dealing with vitrified or frozen oocytes. This is because before vitrifying we have to decumulate the eggs, making conventional IVF impossible. Finally, it is also necessary to do ICSI in a PGT treatment, as in those scenarios, removing all the cells around the egg is necessary in order to avoid contaminating the biopsy sample.
One of the advantages of ICSI is that allows us to avoid fertilisation failures, since the sperm is introduced directly into the cytoplasm of the oocyte. This is something that can not happen if conventional IVF is performed, even when using a normozoospermic sperm sample.
Because of this, it is also advisable to perform ICSI when we have valuable sperm and oocyte samples, which have been preserved due to cancer or other health problems.
Answer from Dr Walker - Fertility specialist
What is ICSI and should I use it for my IVF? Imagine a woman undergoing IVF. If we collect her eggs, we have two main options for fertilization. The first one is putting the eggs in a bath of sperm and simply watching as they fertilize naturally. Alternatively, we can look at the sperm sample under a microscope in order to find a single sperm that looks the best – we would be looking for a sperm which has a normal shape, one head, not too big, not too small, one tail – not two, not three – swimming fast and not just standing in place, et cetera. We would then take that sperm and inject it directly into the egg. That second option is called ICSI.
ICSI was initially developed for men with poor sperm quality and it’s still used for that reason today. However, nowadays, many clinics use ICSI to improve their fertilization rates in all scenarios. Up until ten, fifteen years ago, specialists were worried that some rare abnormalities detected in children born through IVF may be caused by ICSI. What they found out, however, is that ICSI is not the cause. Rather, defects may be caused by abnormalities in the sperm. The technique itself does not seem to be problematic.
Who should use ICSI? Like I mentioned, it tends to be used in men with low quality sperm, as well as those who don’t produce any sperm within their ejaculate, but who do have sperm inside their testes. There are also some female factor related scenarios in which ICSI may be recommended. For instance, women undergoing IVF who are only able to produce one or two eggs per cycle, ICSI maximizes the fertilization rate. Those who produce eggs with very thick shells are also candidates for the procedure. In general, we would also recommend ICSI to those who tried conventional fertilization without success, as well as those who underwent several IVF cycles without success. Patients who plan to perform PGT-A testing also should consider ICSI, as in that case, maximizing the number of embryos is a priority.
Answer from Dr Arqué - International Medical Director
ICSI is a laboratory technique – the name is an acronym of “intracytoplasmic sperm injection”. Whenever we perform an IVF cycle, there are two ways of fertilizing eggs. The first one is called “conventional IVF” and it basically involves placing an egg in a petri dish of sperm and allowing nature to take care of the rest. ICSI is the other way: in ICSI, we manually select the best looking sperm (with the best morphology and motility) and we inject it directly into the egg.
It’s difficult to recommend ICSI without knowing the particulars of each case – for some patients, one approach may be better than the other. In general, however, ICSI is indicated in cases in which we’re dealing with low quality sperm, or in cases where the patient experienced fertilisation failure. Otherwise, either technique can work just as well as the other; it usually falls to the biologist in the lab to make the decision based on the quality of the sperm and eggs.