ICSI stands for intra-cytoplasmic sperm injection. It is a gold standard technique used for overcoming severe male infertility, after repeated unsuccessful attempts with in vitro fertilization or egg freezing. The procedure involves the injection of a single, healthy sperm directly into the cytoplasm of the female egg so as to induce artificial fertilization and obtain the embryo. ICSI has proved to be the most successful form of IVF treatment as the procedure gives the doctors the power to choose the most viable sperm.
For fertilization to take place normally, the head of the sperm must attach to the ovum and penetrate through the outer layer so as to reach the cytoplasm, where the procedure actually takes place. However, in certain cases, the sperm is not able to push through the outer wall of the ovum owing to a plethora of reasons, one of the most common of which is male infertility.
Male infertility refers to the inability to impregnate a fertile female even after persistent efforts.
ICSI may also be recommended for any of the following reasons:
1. The outer wall of the ovum, i.e. zona pellucida, is very thick and does not allow the sperm to penetrate on its own.
2. Previous failed attempts with IVF
3. The thawed sperm is not very active (In case frozen sperms and oocytes are being used)
4. If PGD or preimplantation genetic screening is being done as natural fertilization can interfere with the results.
Sperm retrieval is the most important step in ICSI procedure which can be done in various ways depending upon the cause of infertility and its severity.
Before retrieving the ovum, it is very important to carry out ovarian stimulation for egg harvesting. This is done by administering certain hormones to facilitate the production of more eggs. The female is required to undergo regular tests and screenings to trace the progress of the procedure and to enable the doctors to take the necessary measures for optimizing egg development and numbers.
The egg is retrieved post 34 to 36 hours of administering the final injection. The female is sedated and transvaginal ultrasound aspiration technique is used to carefully remove the eggs from the follicles, with the help of the suction device. The eggs, thus collected, are preserved in nutritive liquid and incubated to be used for fertilization.
1. The matured egg is held with the help of a specialized pipette.
2. The healthy sperm is picked up with using a hollow and delicate needle which is carefully injectedthrough the outer wall of the egg, into the cytoplasm.
3. The needle is removed and the egg is monitored for the evidence of fertilization.
4. Soon after the fertilization takes place, the embryo is placed inside the uterus of the female partner where it grows naturally.
5. Blood tests and ultrasounds are carried out from time to time to determine if the implantation was successful as well as to trace the progress of the pregnancy.