When ICSI is used

• 1

  Severe male factor infertility

  Low sperm count, poor motility, or abnormal morphology that would make conventional IVF fertilization unlikely to succeed.

• 2

  Previous failed fertilization with conventional IVF

  If a prior cycle resulted in few or no fertilized eggs, ICSI can improve outcomes in a subsequent attempt.

• 3

  Use of surgically retrieved sperm

  For men who've had a vasectomy or have an obstruction, sperm retrieved surgically often requires ICSI for fertilization.

• 4

  Use of frozen or donor sperm

  ICSI can help ensure fertilization when sperm quality after freezing or processing is variable.

• 5

  Cases planning genetic testing

  ICSI helps avoid contamination from extra sperm attaching to the egg, which matters for accurate preimplantation genetic testing (PGT) results.

The ICSI process, step by step

• 1

  Egg retrieval

  Eggs are retrieved in the same way as a standard IVF cycle — ovarian stimulation followed by egg retrieval.

• 2

  Sperm preparation

  Sperm are prepared and evaluated under a microscope to identify healthy, viable candidates.

• 3

  Injection

  An embryologist selects a single healthy-looking sperm and injects it directly into each mature egg using a specialized microneedle.

• 4

  Culture & monitoring

  Fertilized eggs are cultured and monitored in the same way as conventional IVF embryos.

What determines ICSI success

• Egg quality — since ICSI bypasses natural sperm selection, egg quality remains a key factor in fertilization and embryo development.
• Sperm quality — even with ICSI, sperm DNA integrity affects embryo development, though ICSI directly addresses many motility and count-related barriers.
• Embryologist experience and lab conditions — ICSI is a technically precise, hands-on procedure, so the skill of the embryologist performing it matters.
• The underlying cause of infertility being treated.

ICSI safety & what to expect

ICSI has an extensive history of use since the 1990s and is now a well-established part of fertility treatment worldwide. Research has looked at whether ICSI carries any additional considerations compared to conventional IVF, particularly for cases involving significant male-factor genetic causes — this is worth discussing directly with your doctor if genetic counseling is relevant to your specific situation.

Is ICSI used for every IVF cycle?

No — it's used specifically when indicated, such as for male factor infertility, prior fertilization difficulty, or when genetic testing is planned, rather than as a routine default for every case. Whether ICSI is the right approach for your cycle is a decision made based on your specific evaluation.