ICSI IVF

Many couples who are undergoing IVF have queries about the procedure and one of the common topics is ICSI. Here we explain in detail and answer all possible queries related to ICSI so that the couples are well aware and prepared before they start the procedure.

What is ICSI?

ICSI stands for Intracytoplasmic Sperm Injection. During the procedure of IVF, the fertilization of the egg by the sperm takes place in the IVF Laboratory. This can happen in two ways-

  1. Natural/Conventional– The woman’s eggs are surrounded by the sperms in a petri-dish and one sperm fertilizes the egg. This is a “best sperm wins” scenario as in happens in natural conception.
  2. ICSI– Intracytoplasmic sperm injection. Here the husband’s semen sample is prepared and the best sperms are chosen. Then with a very fine ICSI needle a single sperm is injected into the egg. This is how the sperm fertilizes the egg.

What is the difference between ICSI and IVF? / How is ICSI different from IVF?

The basic difference between ICSI and IVF is the way the sperm fertilizes the egg. IVF is the technique that was developed first and ICSI is a variation of this technique.

  • As a patient there is no difference in the treatment plan whether IVF is done or ICSI is done. The injections, ultrasounds, and follow-up visits remain the same and so does the procedure of egg pick up and embryo transfer. The only difference is what takes place in the IVF lab.
  • By IVF, it is implied conventional IVF. In this, the sperms are left in a petri-dish around the egg to fertilize the egg naturally.
  • In ICSI, the embryologist uses a very fine ICSI needle, and under the microscope, injects one sperm into one egg. Thus, ICSI bypasses the stage where the sperm naturally penetrates the egg. ICSI requires more skill and expertise!

When is ICSI done?

In ICSI, a single sperm is carefully injected into a single egg. This is done in the following key 7 situations

  1. Oligospermia: When the sperm count is very low.
  2. Teratozoospermia or asthenozoospermia: When the sperms have low motility or abnormal morphology.
  3. When frozen sperms are being used for IVF.
  4. When testicular sperms are being used for IVF.
  5. Previous history of fertilization failures in IVF.
  6. Multiple IVF failures in the past.
  7. When PGS or embryo biopsy is planned.

Is ICSI treatment painful?

No, ICSI is not a painful procedure. During the process of IVF/ICSI, the patient is anxious about the procedure being painful. However, there is no part of the procedure in which the patient may experience pain.

  • The injections given during the IVF/ICSI procedure are with a very fine needle just like the insulin injections that the diabetics take. The needle is very fine and does not cause pain.
  • The patient is given general anesthesia during egg pick up. Under anesthesia, she does not experience any pain.

Is IVF or ICSI more successful?

Both IVF and ICSI are equally successful. The right treatment choice depends on the indication and history of the patient. In the following conditions, ICSI will be more successful and will give better results

  1. Male factor infertility with a low sperm count or decreased motility.
  2. Abnormal morphology
  3. Testicular sperms
  4. Frozen sperms
  5. Previous history of multiple IVF failures.

In the rest of the cases, IVF and ICSI both have equally good results. This is so because the embryo formed by either IVF or ICSI has the same implantation rates. Whether IVF or ICSI is used for the formation of the embryo is immaterial.

Does ICSI affect gender?

No, ICSI does not affect the gender. The gender of a baby is determined by the sperm which may carry the X or Y chromosome. If a sperm carrying the X chromosome fertilizes the egg, it results in a baby girl. If a sperm carrying the Y chromosome fertilizes the egg, it results in a boy. During ICSI, there is no sperm selection for the determination of gender. Therefore, ICSI does not affect gender.

According to the longest-running study till date, ICSI babies do not face any more health problems than babies born by natural means.

How do they choose the best sperm for ICSI?

During ICSI, the semen sample is prepared by using techniques like the Double Density Gradient to choose the best and fast-moving sperms. The embryologist then picks up one sperm with the ICSI needle and gently deposits it in the egg.

Can ICSI cause twins?

No, ICSI does not cause twins.

  • The process of ICSI per se has no effect on the rate of twins. ICSI is simply the process by which the sperm is injected into the egg for fertilization. This results in the formation of embryos.
  • The rate of twins or multiple pregnancy is affected by the number of embryos transferred into the uterus of the patient. If a couple absolutely does not want twins, then only a single embryo is transferred into the womb.

Is ICSI safe for the babies?

Yes, ICSI is safe for the babies.

  • Some patients feel that ICSI damages the egg when the sperm is mechanically injected into the egg with the needle. However, it is not true. If an expert embryologist performs the procedure of ICSI, the chances of egg damage are very less, less than 2 %.
  • Some people feel that if an unhealthy sperm is chosen and injected into the egg, the baby may be abnormal. But, there have been millions of ICSI cycles resulting in the birth of healthy babies to disprove this theory.
  • Some couples ask us whether there is an increase in birth defects after ICSI. The answer is “No”. Men with azoospermia because of Y chromosome microdeletion and who opt for ICSI will have the risk of transmitting it to the baby. But men with normal chromosomes undergoing ICSI will have kids with normal chromosomes. Thus, the process of ICSI per se does not transmit or cause any genetic problems.

Can ICSI cause birth defects?

No, ICSI does not cause birth defects.

  1. Though some studies initially showed that ICSI may be associated with increased birth defects like hypospadias, Angelman Syndrome, Beckwith-Wiedemann syndrome, and sex chromosome abnormalities. However, whether these defects are due to the ICSI procedure or due to the underlying subfertility is not proven.
  2. Still other studies suggested an association between ICSI and increased risk of autism, intellectual disabilities, and birth defects compared with IVF but these increased risks may also be due to the effects of subfertility.

Therefore, it is yet to be conclusively proven that ICSI may increase birth defects. The ICSI procedure itself does not lead to any birth defects.

How many sperm do you need for ICSI?

By the procedure of ICSI, one sperm is injected into one egg. Thus, theoretically speaking, only one sperm is needed to fertilize the egg and conceive by ICSI.

However, the procedure of IVF/ICSI has attrition at every step. Not all eggs that are retrieved may be mature. Similarly, not all sperms are of good quality. Also, once the sperm enters the egg , not all eggs are fertilized. The embryos thus formed have varying quality and not all embryos may be worth transferring.

Considering all these factors, it is important to understand that there should be enough good quality eggs and sperms to result in formation of good embryos.

Can ICSI damage the egg?

No, generally ICSI does not damage the egg. When done carefully by an expert embryologist, the risk of damage is very less, less than 5 %.

How many eggs fertilize with ICSI?

Nearly 70 to 80 percent of eggs fertilize with ICSI. During the process of natural fertilization, there is a possibility that the sperm may not penetrate and fertilize the egg resulting in “fertilization failure”. Since in ICSI, the sperm is injected directly into the egg, it facilitates the process of fertilization. The fertilization rates are markedly improved in cases of male infertility with poor sperm count.

Why do eggs not fertilize with ICSI?

Eggs may not fertilize with ICSI in some cases due to certain reasons. It may be due to:

  1. The sperm head not been able to decondense or
  2. Due to failure of egg activation.

How long does it take eggs to fertilize with ICSI?

The procedure of fertilization check is done 17-18 hours after ICSI. Once the egg pick-up is done, the procedure of ICSI to inject the sperms into the egg is done after nearly 4 hours. The visible signs of fertilization which tell us that it has happened successfully appear after 17-18 hours. Fertilized eggs show the presence of 2 polar bodies and 2 pronuclei.

How long does ICSI take?

ICSI involves injection of one sperm with a fine needle into the egg. The procedure takes on an average 10-15 minutes. Prior to ICSI the sperms are prepared which may take 40-45 minutes.

Is ICSI cheaper than IVF?

No, ICSI is not cheaper than IVF. ICSI involves the use of a fine needle to inject a sperm into the egg. This involves an additional cost of nearly Rs 15,000.

Is IMSI better than ICSI?

  • IMSI stands for Intracytoplasmic Morphologically Selected Sperm Injection. It is a technique in which a high power microscope is used to assess the sperm morphology and select sperms that are normal and without any defects. These are then injected into the egg by Intracytoplasmic Sperm Injection (ICSI).
  • IMSI helps the embryologist to identify tiny defects in the sperm head that would not be visible in standard ICSI.
  • In male factor infertility, it helps in improving the implantation and pregnancy rates than conventional ICSI.

What causes ICSI failure?

There can be several causes of ICSI failure. Normally the success rate of ICSI is 70 to 80 %. However, ICSI failure can happen in 2 ways

  1. In nearly 20 to 30 percent the eggs may still not be fertilized by the sperm. This is mainly due to sperm abnormalities. Out of 10 eggs nearly 8 fertilize.
  2. Total Fertilization Failure: It is an entity in which none of the eggs fertilize after ICSI. It occurs in 5-10%of the cases. The main causes are
    • Poor egg quality
    • Poor sperm quality
    • Abnormal oocyte activation: Normally when the sperm enters the egg, oocyte activation takes place which leads to the other steps of fertilization and embryo formation. At times this crucial step may not occur and may require artificial activation.

Why would ICSI not work?

ICSI does not work in 5 to 10 percent of cases where there may be Total Fertilization Failure (TFF). This may happen in some cases and the main reasons are:

  1. Abnormal Oocyte activation: It happens when the sperm enters the egg but activation of the egg does not occur. Artificial Oocyte Activation (AOA) can be done using calcium ionophore which induces calcium oscillation and initiates the oocyte activation.
  2. Poor egg quality
  3. Poor sperm quality

Does ICSI increase risk of miscarriage?

No, ICSI does not increase the risk of miscarriage. The major factors causing miscarriage in IVF pregnancies are actually the underlying reasons that cause a couple to seek fertility treatment in the first place. Most common reasons of early pregnancy loss can be

  • Genetic abnormality of the embryo
  • Implantation dysfunction: where the uterus is not receptive to the embryo.

What happens after ICSI?

After ICSI, the process of fertilization occurs.

  • Once the sperm is injected into the egg by ICSI, a fertilization check is done after 18 hours to assess how many eggs have fertilized. Usually, 7-8 eggs out of 10 fertilize after ICSI.
  • Then the fertilized egg or zygote progresses further and divides into cells to form the embryo.
  • This growth is monitored in the IVF laboratory over the next 3 to 5 days. Once the embryo is formed, it is transferred in the wife’s womb by the process of embryo transfer.

Does ICSI affect embryo quality?

No, ICSI does not affect embryo quality in any way. There appears to be no difference in embryo quality between ICSI and non- ICSI embryos. Also, there is no difference in the pregnancy rates between ICSI and non-ICSI embryos.