Intracytoplasmic sperm injection (ICSI) is a fertilisation technique in which a single sperm is injected directly into an oocyte using a fine glass needle under high-power microscopy. In standard IVF, tens of thousands of sperm are placed with each egg and fertilisation occurs naturally. ICSI is used when sperm count, motility, or morphology is severely abnormal, when sperm are surgically retrieved (TESE or PESA), or following previous fertilisation failure.
Cryopreservation implications
ICSI uses the same vitrification protocols and liquid nitrogen storage as standard IVF for any resulting embryos. Where surgically retrieved sperm are used, the TESE or PESA sample is typically cryopreserved in cryovials at -195.8°C and thawed on the day of use if not used fresh. ICSI now accounts for the majority of fertilisation attempts in UK IVF cycles.
Cryolab supplies cryopreservation equipment and consumables to UK IVF and andrology laboratories. Visit cryolab.co.uk or call 01243 781 121.
