Intracytoplasmic Sperm Injection

Intracytoplasmic Sperm Injection (ICSI) is a technique where we take a single sperm and it is put into a single egg. It is a technique where fertilization occurs outside the body (in vitro fertilisation). It helps couples facing issues with male fertility like low sperm count, or poor sperm motility. It helps couples in improving their reproductive health by overcoming infertility issues.

This Story also Contains

1. Definition Of Intracytoplasmic Sperm Injection
2. Biological Basis Of Intracytoplasmic Sperm Injection
3. Intracytoplasmic Sperm Injection Procedure
4. ICSI Applications And Advances
5. Recommended Video On 'Intracytoplasmic Sperm Injection'
6. MCQs on Intracytoplasmic Sperm Injection

ICSI is a step further where we double ensure that fertilization happens to a maximum extent. It is mainly used to improve the chances of conceiving and when the standard IVF procedure is not successful. It has become a valuable tool in addressing infertility, since it directly supports human reproduction. This article talks about biological basis, procedure, potential risks, advantages and advances.

Definition Of Intracytoplasmic Sperm Injection

ICSI is a specialised form of assisted reproductive technology (ART) used to treat male infertility. In this procedure, a healthy and active sperm is directly injected into the egg’s cytoplasm under a microscope. It helps to achieve fertilization when it is not possible to conceive naturally by overcoming the natural barriers.

ICSI has become a widely used option in fertility clinics due to its improved success rates. It allows couples with severe male infertility to have a chance at getting pregnant.

Biological Basis Of Intracytoplasmic Sperm Injection

The biological basis of ICSI lies in understanding the roles of sperm and oocytes in natural fertilization. In ICSI, this natural process is skipped and fertilization occurs by introducing a single sperm directly into the egg.

Sperm Structure And Function

The structure of sperm comprises three parts:

1. the head, which contains the nucleus and carries the genetic material

2. the midpiece, which accounts for the energy with its mitochondria

3. the tail, which is mainly involved in the movement.

Role of Sperm in Fertilisation: The sperm transfers its genetic material into the oocyte, which results in the formation of embryo.

Structure And Functions Of Ovum

The structure of ovum is a large, round cell surrounded by a protective outer layer, the zona pellucida. It has a nucleus with genetic material and organelles to support early embryonic development.

Role of the Oocyte in Fertilization: The oocyte provides the right environment and support for the sperm to enter. This leads to fertilization and then the development of the embryo.

Process Of Fertilisation

Natural Fertilisation vs. ICSI: In the natural process of fertilisation in human and implantation, the sperm enters inside the egg by chemical and physical interactions, leading to embryo formation and attachment to the uterus. Whereas in ICSI, a single live sperm is manually introduced into the egg using a needle without any chemical signals.

Steps of Natural Fertilisation: First, the sperm reaches the outer layer of the egg (called zona pellucida). Then, the membranes of sperm and egg are fused together and a zygote is formed.

Intracytoplasmic Sperm Injection Procedure

ICSI is a delicate four-step process which is used to help couples facing issues with infertility. This process increases the chances of fertilization by directly injecting a sperm into the ovum, overcoming the natural barriers and supporting the stages of pregnancy-parturition-lacatation. Here are the steps involved in the ICSI process:

Indications For ICSI

• Factors affecting male fertility: This may be a reduced number of sperm, diminished motility of the sperm, or abnormal morphology.

• Factors affecting female fertility: These may include a problem with the quality of the eggs, any past fertilization failure during IVF treatment, or hormonal imbalances.

• Unexplained Fertility: This is after performing all the usual tests. Doctors cannot find a specific reason for why a couple is unable to get pregnant.

Preparation For ICSI

• Sperm Collection and Preparation: Sperm is collected either through normal ejaculation or by using medical techniques if needed. After that, healthy and active sperm are chosen and kept aside for insertion into the egg.

• Ovarian Hyperstimulation and Oocyte Retrieval: Hormone injections are given to females according to the phase of the menstrual cycle. This is done to produce multiple ovaries instead of just one. Once the eggs are ready, a doctor carefully removes them using a minor surgical aspiration technique.

ICSI Method

Micro-manipulation Tools and Equipment: Specialized microscope and other tools like micropipettes and micro-manipulators to handle sperm and oocytes.

Step-By-Step Process Of Injecting A Single Sperm Into An Oocyte

ICSI requires very delicate handling of sperm and eggs using advanced tools. This process requires great skills and is done in the lab under controlled conditions to avoid any mistakes. The following steps are involved:

• Sperms and oocytes are placed under the microscope.

• Single sperm is then picked up and immobilized.

• The sperm taken from the sample is then injected into the cytoplasm of the egg in a petri dish using a fine needle.

• After the sperm is injected, the egg is observed if fertilization has occurred. If the egg is successfully fertilized, an embryo is formed which is monitored over the next few days.

• Once the embryo develops into blastocyst, it is gently placed into the uterus. Implantation into the uterus lining leads to pregnancy.

Success Rates And Outcomes

ICSI has a good success rate and it has helped many couples overcome the disorders of human reproductive system. However, not every attempt leads to pregnancy. Success rates and outcomes of ICSI can be determined by several factors, such as:

• Age of the woman: Young women usually have higher chances of success because of healthier eggs.

• Quality of the egg and sperm: Good quality of eggs and active sperms increases the chances of pregnancy

• Health of Uterus: A healthy uterus is important for the attachment and growth of embryo

• Comparison with Other ART Methods: In most cases of severe male infertility, ICSI is generally more successful compared to the noninvasive methods used in traditional IVF.

Potential Risks And Complications

• Risks to Mother and Child: OHSS, multiple pregnancies, and long-term health effects of the practice of the child potentially.

• Long-Term Outcomes and Ethical Considerations: To screen children for development problems and controversial ethics issues of embryonic and embryo selection and handling.

ICSI Applications And Advances

ICSI Applications continuously evolve with advancements in technology, making this treatment more successful and versatile.

Advances In Technology

• New Manipulation Techniques: They limit human interference and include advanced tools and techniques that are used to inject sperm into the egg and carefully handle embryos

• Genetic Testing and Embryo Selection: The new and modern genetic tests can check embryos to find any abnormalities and reduce the risk of passing on genetic disorders.

Future Of ICSI

• Research Trends and Milestones: Increase in the success rates, minimization of risks, and using the techniques in other situations as well.

• Ethical and Societal Implications: Selection of the embryo, genetic manipulation, and accessibility to treatments.

Recommended Video On 'Intracytoplasmic Sperm Injection'

MCQs on Intracytoplasmic Sperm Injection

Q1. Which of the following is a technique of ART where sperm is directly injected into the egg?

1. Intrauterine Insemination (IUI)

2. Intracytoplasmic Sperm Injection (ICSI)

3. Gamete Intrafallopian Transfer (GIFT)

4. Zygote Intrafallofian Transfer (ZIFT)

Correct answer: 2) Intracytoplasmic Sperm Injection (ICSI)

Explanation:

Intracytoplasmic Sperm Injection (ICSI) is a technique of ART where a single sperm is directly injected into the egg. It is commonly used in cases of male infertility, such as low sperm count or poor sperm motility.

Hence, the correct answer is option (2) iv only.

Q2. Which of the following techniques is used to treat male factor infertility?

1. Intrauterine insemination (IUI)

2. Gamete intrafallopian transfer (GIFT)

3. Zygote intrafallopian transfer (ZIFT)

4. Intracytoplasmic sperm injection (ICSI)

Correct answer: 4) Intracytoplasmic Sperm Injection (ICSI)

Explanation:

Intracytoplasmic sperm injection is a kind of in vitro fertilization which involves injecting a single sperm right into the cytoplasm of an egg. It is specifically very helpful in cases where both partners have issues with male fertility, such as low sperm count, poor motility, and abnormal morphology. ICSI gets around natural resistance to fertilization, thereby ensuring a better conception rate where IVF methods will not work. It typically occurs following ovarian stimulation and oocyte retrieval, and it is fertilized 16-18 hours post-injection.

Hence the correct answer is Option (4) Intracytoplasmic sperm injection (ICSI)

Q3. In what cases is ICSI commonly used?

1. Female factor infertility

2. Male factor infertility

3. Both female and male factor infertility

4. None of the above

Correct answer: 2) Male factor infertility

Explanation:

CSI is commonly used in cases of male factor infertility, where the male partner has low sperm counts, poor sperm motility, and poor quality of sperm to penetrate the oocyte. In such cases, conventional IVF may not be effective, and ICSI offers a higher chance of successful fertilization. In ICSI, a single sperm cell is directly injected into the cytoplasm of the ovum, bypassing any barriers to fertilization that may be present in the male partner's sperm. This technique has revolutionized the treatment of male factor infertility and has helped many couples to achieve pregnancy.

Hence, the correct answer is Option (2) Male factor infertility.

Also Read:

• MCQs on Intracytoplasmic Sperm Injection (ICSI)

• Reproductive Health

• Disorders of Human Reproductive Systems