ICSI (intracytoplasmic sperm injection)
A fertilisation technique in which a single sperm is injected directly into an egg using a fine needle.
In plain English
It's a way of fertilising an egg by injecting one chosen sperm directly into it, rather than leaving fertilisation to happen on its own in a dish.
Why it matters
It's typically recommended for male factor infertility, but many clinics now use it more broadly, so it's worth asking why it's suggested in your case.
Related terms
Guides that cover this
Sources
- IVF: what is IVF and how does it work?, HFEA (UK fertility regulator). Link checked 17 September 2026.
Written by patients, not clinicians. This page has not yet been reviewed by a named fertility professional, so it explains published guidance and points you to the original source instead of giving medical advice. It is not medical advice. Decisions about your treatment belong with your own clinic. Read our editorial policy and corrections policy.