ICSI is a variation of IVF and it is basically used for cases of few, poor quality eggs (oocytes), disease-threatened or poor quality sperm or when previous attempts with IVF have failed.
It involves injecting one sperm cell (spermatozoon), that has been previously selected in the laboratory, into each of the mature oocytes that are taken from you ovary. In this procedure the oocytes have to be extracted and transferred to the laboratory to be fertilised by either your partner’s or donor’s sperm cells (spermatozoa). At this stage the embryos obtained are put in culture mediums for between two and five days until they can be transferred (a maximum of three) into your uterus where they continue to develop.
The other embryos left over which are considered to be viable are cryopreserved so that they can be used later on in another cycle if you so wish or you can donate them to other couples or for research, in accordance with the Spanish Law on Assisted Reproductive Techniques.
If sperm is also needed for this procedure, bear in mind that all the donors are of legal age, they are chosen according to their blood group and the physiological characteristics of the recipient, they are completely anonymous, and they have been fully examined to make sure that they have no congenital, genetic disorder or sexually transmitted disease.
To a great extent, the success of this technique depends on the woman’s age. The pregnancy rate per cycle is between 55 and 65%, although this figure rises to over 70% for women who are younger than 35.