What is ICSI? Intracytoplasmic Sperm Injection Explained

What is ICSI in Simple Terms?

ICSI (intracytoplasmic sperm injection) is a fertility procedure where a single sperm is directly injected into an egg to help fertilisation.

Unlike natural fertilisation, where sperm must penetrate the egg on its own, ICSI bypasses barriers that may prevent fertilisation, making it especially useful when sperm quality; such as count, movement or shape, is compromised.

Why is ICSI Used in Fertility Treatments?

ICSI is primarily used to overcome male infertility or address previous IVF fertilisation failures.

Common reasons include:

• Low sperm count (oligospermia)
• Poor sperm motility (asthenozoospermia)
• Abnormal sperm shape (teratozoospermia)
• Previous IVF cycles with poor fertilisation
• Use of frozen or surgically retrieved sperm

By directly injecting a healthy sperm into the egg, ICSI increases the chances of successful fertilisation in these situations.

How is the ICSI Procedure Performed?

ICSI is performed as part of an IVF cycle and takes place over several days in stepwise stages:

• Ovarian Stimulation: Hormone injections stimulate the ovaries to produce multiple eggs. Regular scans and blood tests monitor follicle growth until the eggs are ready.
• Egg Retrieval: Eggs are collected under sedation using a thin needle guided by ultrasound. The procedure usually takes 15-20 minutes, and most patients go home the same day after a short rest.
• Sperm Collection: A sperm sample is collected via ejaculation. If needed, sperm can be retrieved surgically.
• Sperm Selection: In the lab, embryologists select healthy sperm under a microscope, even from samples with low count or motility.
• ICSI Fertilisation: Each mature egg is injected with a single selected sperm using a fine needle, bypassing barriers to natural fertilisation.
• Checking Fertilisation: Eggs are examined the next day for signs of successful fertilisation and early embryo development.
• Embryo Growth: Fertilised embryos are cultured for several days while their growth and division are monitored.
• Embryo Transfer: A healthy embryo is placed into the uterus via a thin catheter. The procedure is usually simple and painless, followed by a waiting period before pregnancy testing.

What Are the Benefits of ICSI?

ICSI helps fertilisation when it is unlikely to happen naturally. Its main benefits include:

• Higher fertilisation rates with poor sperm quality: Direct injection of a healthy sperm into the egg bypasses barriers, improving fertilisation chances when sperm count, motility or shape is abnormal.
• Use of frozen or surgically retrieved sperm: Even limited or non-motile sperm can be used effectively, which is important in severe male infertility cases.
• Reduces risk of fertilisation failure in IVF: Actively assists fertilisation, lowering the chance of failed IVF cycles.
• Compatible with genetic testing: Preferred for pre-implantation genetic testing, as using a single sperm ensures more accurate results.

While ICSI does not guarantee pregnancy, it significantly improves fertilisation chances in cases where conventional IVF may not suffice.

Are There Risks or Complications Associated With ICSI?

ICSI is generally safe, but some risks are important to know:

• Slightly higher risk of embryo abnormalities: Rare and usually linked to existing sperm or egg issues, not the procedure itself.
• Ovarian Hyperstimulation Syndrome (OHSS): Hormone medications used in IVF can cause bloating, pain or fluid retention. Severe OHSS is uncommon with proper monitoring.
• Risk of multiple pregnancy: Transferring more than one embryo increases the chance of twins or triplets; this applies to IVF in general.
• Possible egg damage during injection: A very small number of eggs may not survive the injection, though this is rare with modern lab techniques.

What is the Success Rate of ICSI?

ICSI is widely used in fertility clinics, accounting for about 60% of all IVF procedures because it improves fertilisation chances in cases where standard IVF may struggle.

In skilled labs,50% to 80 % of mature eggs injected via ICSI are successfully fertilised. However, fertilisation does not guarantee pregnancy. Implantation and live birth rates depend on factors such as maternal age, egg quality, embryo health and overall reproductive condition. When used appropriately, pregnancy and live birth rates for ICSI are generally similar to conventional IVF.

How is ICSI Combined With IVF?

ICSI is a specialised step within the IVF process used to assist fertilisation. After eggs are retrieved during an IVF cycle, ICSI can be performed instead of conventional insemination.

Once fertilisation occurs, embryos are cultured and transferred to the uterus in the same way as standard IVF, following the usual protocols.

Are There Alternatives to ICSI?

Yes, alternatives to ICSI include other assisted reproductive techniques depending on the situation:

• Standard IVF: Eggs and sperm are combined naturally in a lab; suitable when sperm quality is normal.
• Sperm retrieval techniques with IVF: Used when ejaculation is not possible, allowing sperm to be obtained surgically.
• Donor sperm IVF: Considered if sperm quality is severely compromised or other treatments have failed.

When Should You Discuss ICSI With Your Doctor?

You should discuss ICSI if male infertility, previous IVF failure or fertilisation difficulties are present. Early consultation helps:

• Assess sperm and egg quality to determine the best approach.
• Plan ovarian stimulation protocols tailored to your needs.
• Set realistic expectations regarding fertilisation and pregnancy chances.

Conclusion

ICSI can be a vital option when fertilisation has been challenging, offering hope in situations where natural conception or standard IVF may struggle. While it’s not suitable for everyone, understanding the procedure helps you make informed decisions and feel more in control of your fertility journey. 

With careful planning, medical guidance and realistic expectations, ICSI can turn uncertainty into possibility, giving many couples a practical path toward achieving pregnancy.