ICSI, Intracytoplasmic Sperm Injection

A variety of abnormalities can contribute to male infertility. Sperm can be completely absent from the ejaculate (azoospermia) or present in low concentrations (oligospermia). Sperm may have poor motility (asthenospermia) or have an increased percentage of abnormal shapes (teratospermia). There may also be functional abnormalities that prevent the sperm from binding to and/or fertilizing the egg.

ICSI involves the injection of a single sperm directly into the cytoplasm of a mature egg.

Intracytoplasmic sperm injection (ICSI) is a laboratory procedure developed to help infertile couples undergoing in vitro fertilization (IVF) due to male factor infertility. Severe male factor infertility, once an impenetrable barrier to parenthood, has virtually ceased to exist with the advent of this technique. ICSI involves the injection of a single sperm directly into the cytoplasm of a mature egg (oocyte) using a glass needle (pipette) under microscopic visualization.

This increases the likelihood of fertilization when there are abnormalities in the number, quality, or function of the sperm. In addition, the number of sperm necessary for successful conception is greatly reduced. ICSI is one of several micromanipulation operative techniques used in assisted reproduction.

Indications for intracytoplasmic sperm injection include:

• low numbers of motile sperm
• severe teratospermia
• problems with sperm binding to and penetrating the egg
• antisperm antibodies
• prior or repeated fertilization failure with standard IVF methods
• “egg factor” cases when there is either a low number of eggs, or lower “quality” eggs (or often both)
• use of sperm obtained from microsurgical epididymal sperm aspiration (MESA), or from testicular sperm aspiration (TESA) limited in number and quality

Fertilization occurs in 50% to 90% of ICSI injected eggs.

Pregnancy following ICSI does not increase the incidence of twins or other multiple gestations when compared to other IVF treatments but is increased when compared to naturally conceived pregnancies. The ICSI process may damage a small percentage of eggs. Because ICSI is a relatively new technique, first performed in 1992, long-term data concerning future health and fertility of children conceived with ICSI is not available. Because some causes of male infertility are inherited, male offspring might develop reproductive problems as adults. Despite these concerns, ICSI is a major advance in the treatment of severe infertility.