ICSI Explained
Understanding Intracytoplasmic Sperm Injection (ICSI)
Intracytoplasmic Sperm Injection (ICSI) is a specialised form of in vitro fertilisation (IVF) used to help fertilisation occur when there are significant problems with sperm or previous fertilisation difficulties. During ICSI, a single healthy sperm is injected directly into a mature egg in the laboratory.
ICSI has helped many individuals and couples achieve pregnancy and is now a well-established fertility treatment. Although it is performed as part of an IVF cycle, the way fertilisation occurs differs from conventional IVF.
What Is ICSI?
During conventional IVF, thousands of sperm are placed around each egg and fertilisation occurs naturally if one sperm successfully enters the egg.
With ICSI, an embryologist carefully selects a single healthy-looking sperm and injects it directly into the egg using a very fine needle under a microscope.
Once fertilisation has occurred, the embryo is monitored in the laboratory before being transferred into the uterus or frozen for future use.
When Might ICSI Be Recommended?
Your fertility specialist may recommend ICSI if:
There is a very low sperm count.
Sperm movement (motility) is significantly reduced.
A high proportion of sperm have an abnormal shape (morphology).
Sperm has been collected surgically from the testicle or epididymis.
Previous IVF treatment resulted in poor or failed fertilisation.
Frozen sperm with reduced quality is being used.
Preimplantation genetic testing (PGT) is planned in some circumstances.
ICSI is not routinely recommended for everyone undergoing IVF, and your fertility specialist will discuss whether it is appropriate for your situation.
How Is ICSI Performed?
ICSI follows the same initial steps as a standard IVF cycle.
Ovarian Stimulation
Hormone medication is used to stimulate the ovaries to produce several mature eggs.
Egg Collection
The eggs are collected during a minor procedure using ultrasound guidance.
Sperm Preparation
A semen sample is collected and prepared in the laboratory. The embryologist examines the sperm and selects those that appear healthiest and most suitable for injection.
Injection of the Sperm
Using highly specialised laboratory equipment, a single sperm is injected directly into each mature egg.
The eggs are then placed in an incubator while embryologists monitor fertilisation and embryo development over the following days.
Embryo Transfer
If suitable embryos develop, one is usually transferred into the uterus. Any additional suitable embryos may be frozen for future treatment.
How Successful Is ICSI?
ICSI can significantly improve the chance of fertilisation in cases of male factor infertility.
However, successful fertilisation does not always lead to pregnancy. The overall chance of having a baby still depends on many factors, including:
Age.
Egg quality.
Embryo quality.
The health of the uterus.
The underlying cause of infertility.
Your fertility specialist will discuss your individual chances of success based on your circumstances.
What Are the Risks?
ICSI is considered a safe and effective procedure.
Possible risks include:
Not every egg will fertilise successfully.
Some embryos may stop developing before transfer.
The usual risks associated with IVF, including ovarian hyperstimulation syndrome (OHSS), multiple pregnancy and miscarriage.
Rarely, damage to an egg can occur during the injection process.
Although ICSI bypasses the natural process of sperm entering the egg, children born following ICSI are generally healthy, and the vast majority develop normally.
Advantages of ICSI
Improves fertilisation rates in severe male factor infertility.
Allows fertilisation using very small numbers of sperm.
Can be used with surgically retrieved sperm.
Offers hope when previous IVF fertilisation has failed.
Forms part of an established and widely used fertility treatment.
Limitations of ICSI
ICSI improves the chance of fertilisation, but it cannot overcome every cause of infertility.
Successful fertilisation does not guarantee that embryos will develop normally, implant successfully or result in a healthy pregnancy.
For many people, more than one treatment cycle may still be needed.
Frequently Asked Questions
Is ICSI the same as IVF?
ICSI is a specialised technique used during an IVF cycle. The main difference is that, instead of sperm fertilising the egg naturally in the laboratory, a single sperm is injected directly into the egg.
Why isn't everyone offered ICSI?
Many people achieve successful fertilisation with conventional IVF. ICSI is usually recommended only when there is a specific reason why fertilisation may be difficult.
Can poor-quality sperm still be used?
In many cases, yes. Even when sperm numbers are very low, embryologists can often identify suitable sperm for ICSI.
Does ICSI increase the chance of pregnancy?
ICSI increases the chance of fertilisation when sperm-related problems are present. However, pregnancy still depends on many other factors, including embryo development and successful implantation.
A Gentle Reminder
Being advised to have ICSI can feel overwhelming, particularly if you've learned that male factor infertility is contributing to your fertility journey. It's important to remember that needing ICSI is simply one of many treatment options available. Advances in fertility medicine have enabled many people with significant sperm-related difficulties to achieve successful pregnancies, and your fertility team will recommend the approach most appropriate for your individual circumstances.