Intracytoplasmic Sperm Injection (ICSI)

Intracytoplasmic Sperm Injection (ICSI), also known as microinjection, is a method where single, live sperm is directly injected into the egg. The approach was designed to aid couples with significant male factor infertility or women who experienced in vitro fertilization (IVF) cycle failure multiple times.

ICSI is a different approach to IVF procedure. During a traditional IVF procedure many live sperm cells are inserted in a petri dish with several eggs. A sperm reaching an egg fertilizes it as if it was in the uterus, meaning it happens naturally. However, there are several factors that may affect this to happen naturally, which might be the reason for infertility, or multiple IVF failure.

ICSI ensures that an egg is fertilized by directly injecting a single, live sperm to the egg. By being a more simple, straight-forward technique compared to traditional IVF, ICSI has replaced traditional IVF as the method of choice for treating infertility in developed economies.

When male factor infertility is the concern or multiple IVF cycle failure experienced, you might be advised to apply for ICSI. There are several reasons explaining why an egg doesn’t get fertilized by sperm naturally. These include:

• Thick egg membrane, which impedes sperm from entering.
• Low sperm count, mobility and quality, which lowers the possibility of natural fertilization greatly. According to a 2021 study, low sperm cell quality affects approximately 50% of couples having infertility problems.
• Problems regarding ejaculation, which might require surgical retrieval of sperm.
• Fertilization after cryopreservation, where eggs and/or sperm previously frozen to be fertilized later.

Woman undergoes ovarian stimulation with fertility drugs and injections in order to develop multiple eggs. These eggs are subsequently retrieved through the vagina using vaginal ultrasonography and incubated in the embryology laboratory under strict circumstances. On the other hand, the sperm sample is obtained by ejaculation, surgical retrieval, or, if frozen, thawing.

Sample is centrifuged with a special medium and this step separates living sperm from the detritus and the majority of the dead sperm. The embryologist then selects and captures one live sperm and injects it with a glass needle into the egg.

Your doctor will monitor the fertilized egg for the following days and make sure that fertilization succeeds. A healthy fertilized egg should split into cells over the course of five to six days, developing into a blastocyst. Then, the blastocyst will be examined to determine if it is ready to be implanted.

Generally, a blastocyst will be ready in this time interval, 5th or 6th day after fertilization. Using ultrasound technology, a catheter will be inserted into your uterus for the egg to be planted. You can book a pregnancy test when your doctor advises.

ICSI doesn’t have a great impact on IVF success rate. However, it presents a solution for the couples having treatment due to unexplained infertility. According to a recent study published in Frontiers, the use of ICSI to treat cases of unexplained infertility does not result in an increase in the number of live births, although it does produce a greater cancellation rate than traditional IVF.

Although it is mostly safe, there are several considerations regarding the ICSI procedure.

• Injection with a needle may damage the eggs with a very low possibility.
• Egg cannot get fertilized after the injection.
• Embryos stop developing after fertilization or implantation.

An egg can be fertilized by only one sperm. However, for both traditional IVF and ICSI, 75% to 80% of the eggs are recovered. So, it isn’t logical to work with only one egg. This is the reason for ovary stimulation. A woman can produce one or two eggs each month. This number isn’t enough to secure a successful pregnancy, considering the success rate of IVF or ICSI, and the possibility that produced eggs are low quality. So ovaries are stimulated through fertility drugs and injections to produce more eggs. And all of the mature and healthy eggs are fertilized.

Successfully fertilized eggs (embryos) are then implanted to the uterus. The number of embryos to be implanted should be carefully determined. Using multiple embryos increases the chances of successful pregnancy, especially for women above 35. However, it can also cause multiple pregnancy, which may give rise to unwanted complications, and the need for multifetal pregnancy reduction.

You should consult your doctor about options available specifically for your case. If you’d like to learn more about ICSI, contact us. According to the ASRM, If a couple has in vitro fertilization with or without intracytoplasmic sperm injection (ICSI), their chances of having a singleton, or multiple pregnancy are the same once fertilization has taken place.