Everything about ICSI: Differences with IVF, step-by-step process, and success rates

In the exciting realm of assisted reproduction, techniques are constantly advancing to offer new opportunities to those seeking to start a family. One of these techniques is ICSI (Intracytoplasmic Sperm Injection), a powerful tool to overcome male fertility challenges.

Are you eager to grasp the intricate details of what ICSI entails, how it is performed in the laboratory, and what its success rates are? In this blog, our specialist embryologist, Álvaro Martínez, will guide you through each step, explain the differences between ICSI and traditional IVF, and provide a comprehensive view of this cutting-edge technique that is revolutionizing the possibilities of conception.

Be prepared to explore the world of ICSI under the guidance of a fertility expert!

infertilidad, causas de infertilidad

What is ICSI?

Intracytoplasmic sperm injection (ICSI) is an in vitro fertilisation technique that involves introducing a sperm directly into the cytoplasm of the oocytes. One of the steps may require anaesthesia.

Who is it Indicated for?

The need for ICSI in assisted reproduction treatments primarily arises due to poor sperm quality. It is used to address male fertility issues such as oligozoospermia (low sperm concentration), teratozoospermia (morphological abnormalities), or astenozoospermia (reduced motility).


However, in Vida Fertility laboratories, whenever patients agree, we use ICSI in our in vitro fertilisation treatments, as it is a technique that enhances pregnancy rates.

ICSI is also required in other circumstances to overcome various infertility causes such as:

  • Implantation failures. 
  • Previous IVF treatments failures.
  • Previous artificial insemination (AI) failures.
  • Immunological infertility due to antisperm antibodies.
  • Back-up microinjection in cases of failed fertilisation using conventional IVF.
  • In Vitro maturation of the eggs.
  • In case of preimplantation genetic testing (PGT).
  • In case of using donor eggs or donor sperm.
  • In case of using frozen eggs.

How is ICSI performed?

The procedure involves the following steps:

  • Ovarian Stimulation: The patient undergoes hormonal therapy to stimulate her growing follicules and optimise fertilisation.
  • Egg Retrieval: Under anesthesia, mature eggs are retrieved from the ovaries through surgical aspiration.
  • Oocyte Denudation or Decumulation: The surrounding tissue of the collected eggs is removed, eliminating cumulus cells to assess the maturity status of the oocytes.
  • Sperm Preparation: Seminal capacitation for an enhanced fertilisation capacity.
  • ICSI: A sperm is selected and injected into the egg.
  • Embryo Culture: Embryos develop in an incubator under optimal conditions.
  • Endometrial preparation: The endometrium is ready to welcome a pregnancy.
  • Embryo Transfer: A catheter is inserted into the vagina to place embryos in the uterus.

>> All You Need to Know About Embryo Transfer <<

  • Embryo Freezing: Untransferred good quality embryos are frozen and stored for future use.

Differences between IVF and ICSI

The distinctions between In Vitro Fertilisation (IVF) and Intracytoplasmic Sperm Injection (ICSI) are crucial in the world of assisted reproduction.

  • In conventional IVF, eggs and sperm are placed together in a culture dish, allowing fertilisation to occur naturally.
  • On the other hand, with ICSI, a single sperm is selected and microinjected directly into the egg, ensuring a higher probability of fertilisation in cases of male fertility issues.

ICSI becomes the preferred choice when there are problems with sperm quality or quantity. Laboratory experts carefully assess each case to determine the most suitable technique. While IVF is a highly effective process, ICSI maximizes success chances in more complex situations.

Our assisted reproduction specialists, like Leonor Ortega, Head of Vida Fertility’s laboratories, are committed to providing you with detailed information about the differences between these techniques, ensuring that every patient receives the most appropriate treatment for their unique situation.

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ICSI Success Rates

Thanks to the precision and control provided by ICSI in selecting and microinjecting a sperm into the egg, fertilisation is optimised, succeeding where conventional IVF might not. This technique has become an essential resource for couples facing fertility difficulties related to male causes.

Experts in the field of assisted reproduction, including Álvaro Martínez, recognise that ICSI has revolutionised how we address male infertility, giving hope to couples striving to build a family.