Microinjection (ICSI)
When ICSI may be preferred and how the procedure is approached in clinical practice.
Microinjection (ICSI): a laboratory fertilisation technique used within IVF.
ICSI involves injecting a selected sperm cell directly into a mature egg and may be considered according to the clinical and embryological situation.

ICSI is a fertilisation technique used in the embryology laboratory.
Intracytoplasmic sperm injection (ICSI) involves the injection of a selected sperm cell directly into a mature egg. It is performed as part of an IVF cycle when clinically and embryologically appropriate.
ICSI does not replace the broader IVF process; it is one of the laboratory methods that may be used to achieve fertilisation.
The indication for ICSI is determined individually.
Male Factor
Marked abnormalities in semen parameters may lead to consideration of ICSI.
Previous Fertilisation Problems
Previous low or failed fertilisation can be relevant to planning.
Surgically Retrieved Sperm
ICSI may be used when sperm is obtained surgically in selected cases.
Laboratory Considerations
Embryology findings and the clinical history are evaluated together.
The procedure is part of a wider embryology pathway.
Mature eggs are identified after retrieval. A sperm cell is selected according to laboratory criteria and injected into the egg. Fertilisation and subsequent embryo development are then monitored.
As with all assisted reproduction procedures, the outcome depends on multiple female, male and embryological factors and cannot be guaranteed.
Frequently asked questions about ICSI
Does every IVF cycle require ICSI?
No. The choice of fertilisation method depends on the clinical history, semen parameters and laboratory considerations.
Does ICSI guarantee fertilisation?
No. ICSI can facilitate sperm entry into the egg, but fertilisation and embryo development still depend on multiple biological factors.