An Introduction to Intracytoplasmic Sperm Injection (ICSI)

IntraCytoplasmic Sperm Injection (ICSI) is when sperm is directly injected into the cytoplasm of the ooctye. This procedure is done if In Vitro Fertilization (IVF) procedures have failed without any specific reason, or if your male partner has a low sperm count. It may also be performed when there is a disorder in the penetration of the sperm into the oocyte.

This is one of the micromanipulation techniques used in the assisted reproductive technologies. Special equipment called micromanipulators are used for injecting perm into the oocyte under high power magnification in a controlled laboratory environment.

Prior to the ICSI Procedure

Hyaluronidase enzyme is used to remove the cumulus mass cells surrounding the oocyte so that it becomes clearly visible. Sperm is suspended in a Polyvinylpyrrolidone chemical to handle it properly. The tail of the sperm is scored to help in fertilization.

Penetration / ICSI

Two microscopic glass tubes are used in the procedure. One glass tube is known as the holding pipette and it is used for stabilizing the egg and another tube is used for taking sperms. Holding pipette is attached to the micromanipulator for better handling. The second tube is referred to as injecting pipette, and it is used to penetrate the outer layers of the egg (zona pellicuda and egg membrane). Then, the sperm is injected in the cytoplasm of the oocyte. After the injection of sperm, oocyte is released and washed with a fresh drop of culture medium.

Monitoring the Embryo

Injected eggs are kept in an incubator at 37 degree Celsius. The next day, the oocyte is checked for fertilization and it is continuously incubated until the embryo culture is completed. It is kept in incubator for embryo culture for a specific duration (2, 3 or 5 days) depending on your reproductive history.

Embryo Transfer

After the embryo culture, good embryo(s) are transferred into your uterus using a catheter, or they can also be cryopreserved for future usage.

Ideal Candidates for ICSI

This process is performed only if:

  • Intra Uterine Insemination (IUI) or In Vitro Fertilization (IVF) has failed to result in pregnancy.
  • Your male partner has abnormal sperm count or severe oligospermia.
  • Your male partner produces fewer good quality sperms or has anti-sperm antibodies in his semen.
  • Your male partner has irreversible vasectomy or no sperm in semen due to the tubal blockage in his reproductive system.
  • Your age is above 35 years and your egg has a thicker Zona pellicuda covering.
  • You have unexplained infertility.

ICSI is another step towards assisting pregnancy in sub fertile couples or couples facing different types of genetic problems in conception. However, the success of this procedure depends on various factors like age and quality of egg and sperm. Only 29% of success is shown when ICSI is performed in women below 35 years of age.