Intracytoplasmic sperm injection (ICSI) is a laboratory technique used as part of IVF. Instead of placing eggs and sperm together and letting fertilization happen naturally, an embryologist injects a single sperm directly into each mature egg.
How ICSI works
The early stages of treatment are the same as standard IVF: ovarian stimulation, monitoring and egg collection. In the laboratory, each mature egg is held steady while a very fine needle is used to place one sperm inside it. The eggs are then monitored to see whether fertilization has occurred.
When might ICSI be suggested?
- When a semen analysis shows a low sperm count, low motility or unusual shape
- When sperm has been retrieved surgically
- When fertilization was low or did not happen in a previous IVF cycle
- When using frozen eggs, or in some cases of genetic testing
Does ICSI guarantee fertilization?
No. ICSI can help overcome some barriers to fertilization, but not every injected egg will fertilize or develop into an embryo. Your specialist can explain how ICSI may affect your individual chances.
Are there any risks?
ICSI is a well-established technique. As with any treatment, there are considerations to discuss, including a small risk of damage to eggs during injection. Your care team can talk through the current evidence with you.
ICSI is a tool, not a requirement. Whether it is right for you depends on your assessment results and history.
This article is for general information only and does not replace individual medical advice. Please speak with your specialist about your own circumstances.
