ICSI (Intracytoplasmic Sperm Injection)

Last updated: March 2026

What is ICSI?

ICSI is a fertilisation technique where a single sperm is injected directly into an egg using a fine glass needle (HFEA, 2021). It is performed as part of an IVF cycle. The only difference is what happens in the laboratory.

When is ICSI recommended?

ICSI is typically used for very low sperm count, abnormal sperm morphology or motility, previous failed fertilisation with standard IVF, surgically retrieved sperm, frozen sperm, or when PGT-A testing is planned (HFEA, 2021).

Success rates

“Success rates for ICSI tend to be very similar to IVF so we don’t publish separate statistics” (HFEA, 2021). A 2024 study (PMID: 38840410) confirmed comparable outcomes in couples without male factor infertility. An earlier Cochrane Review (PMID: 12804403) found no clear benefit of ICSI over standard IVF in the absence of male factor.

The overuse problem

In 2019, 72.7% of all fresh IVF cycles in Europe used ICSI (ESHRE EIM, PMC10694409). Male factor infertility affects roughly 30-40% of couples. The maths doesn’t add up. Nordic countries and the UK split roughly 50/50 between IVF and ICSI. Mediterranean and Eastern European clinics use ICSI in 90%+ of cycles.

ESHRE’s add-ons working group classified routine ICSI for non-male-factor cases as unsupported: no evidence of benefit. Three separate RCTs have now confirmed this. The INVICSI trial (824 women, 6 Danish clinics, Nature Medicine 2025) found cumulative live birth rates of 43.2% for ICSI vs 47.3% for conventional IVF. Not only no benefit: standard IVF actually produced better fertilisation rates per oocyte and more blastocysts on day 5 (Bhattacharya et al., PubMed 40217077).

Why does overuse matter? ICSI adds GBP 1,000-1,375 to the cycle cost in the UK (HFEA). In Germany, roughly EUR 1,000 more. If your sperm parameters are normal and there’s no other indication, you may be paying extra for a procedure that the evidence says adds nothing.

What to ask your clinic

• Is ICSI necessary for my case, or would standard IVF fertilisation be equally effective?
• What is ICSI’s additional cost at your clinic?
• What percentage of your cycles use ICSI? (If the answer is “all of them” and you don’t have male factor, ask why.)
• Will my embryos be cultured to blastocyst stage after ICSI?

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Related research

• ICSI vs IVF: a trial of 824 women found no benefit without severe male factor: the INVICSI trial that tested whether routine ICSI improves outcomes.

Sources

1. HFEA. Intracytoplasmic Sperm Injection (ICSI): https://www.hfea.gov.uk/treatments/explore-all-treatments/intracytoplasmic-sperm-injection-icsi/
2. Bhattacharya et al. INVICSI trial. Nature Medicine, 2025: https://pubmed.ncbi.nlm.nih.gov/40217077/
3. ESHRE EIM. ART in Europe 2019: https://pmc.ncbi.nlm.nih.gov/articles/PMC10694409/
4. Cochrane Review. ICSI vs conventional IVF, 2003 (PMID: 12804403)

This page is for informational purposes only and does not constitute medical advice. Always consult a qualified fertility specialist before making treatment decisions.