ICSI: Assisted Reproductive Technologies

We know that a woman’s ovarian reserve is drastically affected by her age, while gamete production in men never stops. But numerous studies have demonstrated that there is also an age-related decline in sperm quality in men.

Leonor Ortega, director of the IVF-Life laboratory, tells us more about the assisted reproduction technique called ICSI, which is used in 95% of cases at the IVF-Life Alicante clinic.

ICSI or Intracytoplasmic sperm injection

Intracytoplasmic sperm injection (ICSI) is an assisted reproduction technique that allows us to introduce a sperm into the cytoplasm of the oocyte in order to achieve fertilisation.

For ICSI, the embryology team selects and microinjects the best sperm into the egg to be fertilised. This fertilisation technique is generally used when a gamete alteration is detected.

Occasionally, when there is a considerable number of quality eggs, embryologists decide to use a mixed fertilisation technique, in which half of the oocytes are fertilised by conventional IVF  and the other half by ICSI.


What are the criteria for selecting the best sperm?

To guarantee the success of the procedure, the specialist will select those spermatozoa with the greatest fertilisation potential according to their morphology and motility.

At the fertility clinic in Alicante, Leonor Ortega and her laboratory team perform sperm capacitation and, on occasion, an advanced seminogram which, in addition to providing information on the concentration, motility and morphology of the spermatozoa, examines the molecular characteristics of the semen.

These semen molecules are examined, among other tests, by sperm DNA fragmentation or apoptosis:

  • DNA fragmentation test: The percentage of damaged genetic material in the spermatozoa is quantified. Values above 25% imply that the sperm’s ability to fertilise is compromised.
  • Apoptosis, or programmed cell death, provides an indication of the vitality of the cells. If the percentage of apoptotic cells is high, it is necessary to remove these cells from the sample before proceeding with fertilisation

Advanced Seminograms including the above-mentioned tests can be performed in all of the group’s laboratories.

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Success rates with Intracytoplasmic sperm injection (ICSI)

 There are still different beliefs or reasons why some patients still choose the classic or conventional IVF technique, in which the sperm is put in a Petri dish and must fertilise the egg on its own. This is not the case in our clinic, as 95% of IVF-Life patients undergo In Vitro Fertilisation by ICSI.

“Sometimes we also perform mixed fertilisation when the oocyte quality is good. This technique consists of performing a conventional IVF with half of the gametes and an ICSI with the other half. Results show that, if there are no additional problems, the fertilisation rate is very similar in both techniques.”- Leonor Ortega clarifies.

The success rates of both techniques vary depending on:

  • Embryologist’s
  • The cause of infertility of the patient or her partner.
  • Quality of the gametes (eggs and sperm).

However, the ICSI technique allows the direct fusion of egg and sperm, facilitating fertilisation. A sperm with low motility or poor morphology would be more difficult to achieve fertilisation naturally or through the conventional IVF technique.


Differences between IVF and ICSI

Although both assisted reproductive techniques are performed in the laboratory, there are some differences that patients should be aware of:

Intracytoplasmic Sperm Injection (ICSI) was developed to treat cases of severe male infertility when artificial insemination or conventional IVF failed to achieve implantation. Currently, the ICSI technique is used routinely in numerous clinics, including the clinics of the IVF-Life Group.

The main difference is related to the union of the oocyte and the sperm.

Conventional IVF consists of placing the oocyte in a Petri dish with a drop of semen containing millions of spermatozoa. One of them alone will fertilise the egg. It should be noted that good sperm quality is needed to perform this technique. The embryologist’s intervention is minor.

With the ICSI technique, on the other hand, the specialist’s intervention is much greater. They select the best sperm and, after preparing the sperm, they place it directly into the egg with the help of a high-quality microinjector.

Another difference between the techniques is the denudation or decumulation of the oocytes.

There are cells around the egg that the sperm must penetrate in order to achieve fertilisation. With the ICSI technique, the embryologist removes these cells from the cumulus that form the corona radiata to facilitate fertilisation.

With conventional IVF, this oocyte denudation is performed on day 1 after fertilisation, when assessing whether fertilisation has occurred.


Differences between IVF and ICSI


For whom is this treatment recommended?

Although it is the technique of choice for patients with altered seminal factors (altered concentration, motility or morphology), for vasectomised patients, or patients who have undergone chemotherapy or radiotherapy, it is also very commonly performed in patients with poor oocyte quality or previous fertilisation failures.

In these cases, intracytoplasmic sperm injection is necessary.

In some laboratories, it is the patients themselves who choose the reproduction technique they wish to undergo, however, in our clinics we are committed to offering completely personalised care and individualised treatments to all our patients.

Infertility does not have to be related to health. A completely healthy man can still produce poor quality sperm that makes getting pregnant practically impossible.

According to our laboratory director, “At IVF-Life we usually perform Intracytoplasmic Sperm Injection (ICSI) because, in addition to all the benefits this technique offers, it allows us to find any anomaly that could lead to implantation failure and avoid it”.


Does the procedure for ICSI differ from conventional IVF?

The answer to this question is no, the procedure to perform ICSI is the same as in conventional IVF. Generally speaking, the key steps in both techniques are the following:


At IVF-Life we are fully aware of the emotional and psychological difficulties involved in the decision to start a family and not being able to achieve pregnancy.

Starting a fertility treatment is not easy, that’s why, in order to solve any doubt about your particular case, we offer you the possibility to book an online appointment with one of our fertility specialists by filling out this form.