What is ICSI?
ICSI (abbreviation in English for intracytoplasmic sperm injection), is a procedure first developed in 1992 by which a spermatozoa is injected into the egg with a micro needle. Unlike conventional In- Vitro Fertilisation (where the sperm is incubated with the egg in order to give place for the fertilisation), in the ICSI fertilisation is forced by the sperm injection.
This technique was invented to allow male with decreased sperm motility or low number of spermatozoa to become fathers, who were previously destined to perform artificial insemination using semen bank or adopt a child.
The main indications for ICSI are:
Cases of male factor: men with decreased sperm concentration and mobility of it. For these men the chances of success with a conventional IVF is low.
Previously failed cases of fertilisation with conventional IVF.
Cases with valuable semen samples, such as frozen semen from patients with cancer and vasectomies.
When sperm is obtained directly from the testicle, either due to obstruction of different ducts, their agenesis, problems with ejaculation, etc.
Infectious diseases by male such as HIV, hepatitis B or C, in which the risk of contagion in women with conventional IVF would be increased.
An indication would be a low number of oocytes retrieved in ovarian stimulation.
Can the microinjection be performed in all retrieved oocytes?
ICSI can only be performed when the oocytes are mature. Only a part of all oocytes retrieved in one cycle are used. Some oocytes – not good quality – get damaged when the injection of a spermatozoa is performed.
Are all oocytes fertilised?
When all the oocytes are good, achieves a fertilization rate around 70%
Does ICSI affect embryo quality?
The embryo quality between ICSI and conventional IVF are comparable. Some experts think that manipulating the oocyte can alter embryo quality, but it is probably a problem of biologist´s experience, who performs the technique.
If the embryos obtained using ICSI have the same chance of success as using conventional IVF?
Yes, if the embryo quality is comparable.
Can one proceed straight with In- Vitro Fertilisation using ICSI in case of severe alteration of semen?
In cases of severe male factor, prior to In- Vitro Fertilisation using intracytoplasmic sperm injection, it is important to proceed with the study of testicular meiosis to discard genetic abnormalities in sperm that may lead to repeated failures in achieving pregnancy or embryonic abnormalities. In some cases, if there is sufficient amount of spermatogenic cells, this study can be performed in semen.