Intracytoplasmic Sperm Injection - ICSI

Intracytoplasmic sperm injection has been a highly successful therapy in the management of male factor infertility.

Before the advent of micromanipulation techniques, patient having sub-optimal semen parameters or experiencing no or low fertilization in an in vitro fertilization cycle, had few insemination options to promote or assist fertilization. A review of the couple's history is extremely important in determining if ICSI has therapeutic value during an in vitro fertilization cycle.

ICSI in Male Factor Cases

A thorough evaluation of the male patient starting with a semen analysis is beneficial to identify couples at risk for reduced or no fertilization in a conventional in vitro fertilization. Typically, seminal parameters considered insufficient for standard IVF include men with less than 2 million motile spermatozoa per ejaculate, abnormal morphology, or specific spermatozoa defects impairing spermatozoa-oocyte interaction. These patients are treated with the more aggressive therapy of ICSI to achieve appropriate fertilization and subsequent pregnancy outcome. Surgical retrieval of spermatozoa from the testicles or reproductive tract in combination with ICSI is an effective treatment for men with obstructive or non-obstructive azoospermia, ejaculatory dysfunction or complications from cancer treatment. Repeated surgical retrieval of spermatozoa can be avoided by normal cryopreservation if sufficient number of spermatozoa exists.

ICSI Technique

Although the technique of ICSI appears simple in principle, it involves the use of sophisticated instruments and requires adequately trained embryologists to perform. During ICSI, policies and procedures should be used that protect gametes from temperature and pH variations and fluctuations, which may disrupt spindles and contribute to abnormal chromosomal distribution. The female patient is stimulated and oocytes are retrieved for ICSI in the same manner as conventional IVF procedures. Oocytes (female eggs) derived from poor quality stimulations or exhibiting cytoplasm abnormalities may demonstrate higher degeneration rates, abnormal fertilization rates, and pregnancy loss rates. Prior to ICSI the oocytes are denuded of cumulus-coronal cells by exposure to hyaluronidase and gentle aspiration of oocytes with a finely pulled pipet to remove residual cumulus-coronal cells. The ICSI procedure should be carried out in a flat microinjection dish containing a central drop of 10% PVP with resuspended spermatozoa surrounded by peripheral micro drops of HEPES-buffered media for placement of oocytes under oil. The selected spermatozoa is immobilized by gently pushing the tail onto the dish with the end of the injection pipette and loaded into the injection pipette. During the procedure, the oocyte should be held by light suction with the holding pipette in such a way that the polar body is situated at the 6 or 12 o'clock position. The injection pipette containing the immobilized spermatozoa should be gently pushed through the zona pellucida at the 3 o'clock position and through the oolemma into the center of the ooctye. ICSI does not guarantee fertilization but the incidence of complete fertilization failure is low and frequently occurs in cycles with low oocyte yield. ICSI should be available to those patients with previously failed fertilization who demonstrate either abnormal or normal semen profiles and to those patients with spermatozoa concentration and motility too low to expect any success with conventional IVF.

Last updated: August 11, 2008
Reviewed by Dr. Rachel McConnell and her medical staff