What is IMSI? Should I use it for my IVF?

What is it and why IMSI is used? More importantly, for whom this procedure is advised? 

IMSI is the intracytoplasmic morphologically-selected sperm injection. What are the reason of using IMSI? Who should use this procedure? 

Three fertility experts explain IMSI procedure. This week experts in 3on1 #IVFANSWERS are:

  • Dr Natalia Szlarb – Medical Director at IVF Spain – Medical Director at IVF Spain
  • Dr Àlex García-Faura – Scientific Director of Institut Marquès
  • Dr Maria Arqué – International Medical Director at Fertty International

Dr Natalia Szlarb, IVF Spain

Answer from Dr Szlarb

Intracytoplasmic sperm injection is used for majority of cases of patients with low sperm motility. There are severe cases of teratozoospermia where the number of good-looking, healthy sperm cells is low and then there is a need of intracytoplasmic sperm injection after magnification of sperm at least 6-8 million times to secure the best results. Eventually, in IVF-Spain intracytoplasmic sperm injection is used but the goal is to develop genetically normal healthy embryo and the fertilization at this moment is not that important.


Dr Àlex García-Faura, Institut Marquès, Spain

Answer from Dr García-Faura Scientific Director

IMSI or Intracytoplasmic Morphologically-selected Sperm Injection, also known as Super-ICSI is a sperm selection technique based on spermatozoa morphology. In order to do IMSI we use specific microscopes that will help us magnify the head of spermatozoa up to 16,000 times, instead of standard microscopes that magnify only up to 400 times. This way we select the best spermatozoa, one by one, in order to perform ICSI and inseminate oocytes, also, one by one.
This technique is recommended for patients with an abnormal semen analysis where only 1-3 % of spermatozoa are normal from a morphological point of view. It’s also recommended for patients with long-term sterility and repeated IVF failures.
In this specific group of patients IMSI has shown to give us a higher pregnancy rates and lower miscarriage rates.


Dr Maria Arquè, Fertty International, Spain

Answer from Dr Arqué - International Medical Director

IMSI is a technique that is very similar to ICSI. ICSI is the acronym for intracytoplasmic injection of the sperm. That means what the biologists do in the lab, in the sperm sample, they look for the sperm that looks and moves the best and, then, they select those sperm to inject inside the eggs to try to fertilize them. When we use IMSI, what the biologists do, they use another kind of microscope with bigger potency and, then, they also select the sperm according to its morphology. There are some small studies saying that maybe in patients who have low morphology, patients who have teratozoospermia in the sample, IMSI might help to have better results and to diminish the risk of miscarriage or the risk of having embryos that do not implant. Nevertheless, those studies are very scarce, not conclusive, there is no evidence to support that. In our experience, we have seen very similar results with ICSI or IMSI so this is why we do IMSI in our clinic. One of the techniques that we use especially when we find alterations in the DNA of the sperm, when we find that the DNA fragmentation is high, we use a device that is called Fertile that helps to select better sperm that is less fragmented and we have seen very good results with that technique: it reduces the risk of embryos that are chromosomally abnormal and, also, the risk of miscarriages.


3on1 IVFanswers - three answers to one question

Three IVF experts answering the same question.

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