ICSI
A single selected sperm is injected into each mature egg. Especially helpful when there is a male factor.
Intracytoplasmic sperm injection (ICSI)
Intracytoplasmic sperm injection was developed to overcome the barriers that can stop sperm from reaching the inside of the egg. It is used for couples with a severe male factor, for example a low sperm count with poor motility (oligoasthenozoospermia).
In ICSI, the best sperm are selected after special preparation, and a single motile sperm is used to fertilise each egg. The method can be used for all mature eggs.
Because fertilisation and healthy embryo development are influenced by genetic factors, we recommend that the couple have a genetic analysis (karyotype) before ICSI.
How it is done
The main difference from conventional IVF is how the eggs and sperm are handled in the laboratory. Ovarian stimulation, egg retrieval, sperm collection and embryo transfer are the same as in conventional IVF.
In ICSI, the eggs are placed briefly in hyaluronidase to remove the surrounding granulosa cells, while the sperm is prepared so that it undergoes the acrosome reaction. The egg is then held with the polar body at the 6 or 12 o’clock position, and a fine micro-needle containing the sperm is guided into it.
After the injection, the egg stays in a special culture medium in an incubator with controlled temperature, pH and CO₂ levels, just as in IVF.
Within 48–72 hours, the IVF laboratory can see whether the embryos have developed and are suitable for transfer.
Success rates
With ICSI, the fertilisation rate of mature eggs in our laboratory is 97%, higher than with conventional fertilisation, even when sperm quality is low.
Risks
The risks are similar to those of conventional IVF.
Medical content by the Fertility Clinic team