If the sperms will not fertilize the eggs naturally, ICSI is the most successful technique to overcome the failure in which a single spermatozoon is deposited directly into the cytoplasm of the oocyte. Number of sperms is immaterial for ICSI but motile sperm brings better results because of its morphology. It revolutionized the treatment of male infertility in early 1990's. It allows men with little, or sometimes no sperm in their ejaculate to create a genetically related child.

Complete failure of fertilization is very rare in ICSI. ICSI gives hope in cases of severe oligospermia and even azoospermia. It bypasses the ovolemma and zona pellucida of eggs. In azoospermia spermatids are obtained from epididymus ( MESA , PESA) or testes (TESE). In MESA or TESE, elongated spermatid is better. Results from mechanical immobilized sperms are better. It also helped to understand better some key steps of fertilization process.

Unfortunately there were, and are, no effective treatments to increase sperm quantity & quality unless there is a specific, responsive cause such as a blockage or severe hormone imbalance.

Higher fertilization and pregnancy rates regardless of sperm characteristics make ICSI the best procedure yet to treat male factor infertility. It is independent of basic sperm factors, i.e. concentration, morphology and motility. ICSI is a laboratory procedure adopted when:

• Semen parameters are grossly abnormal; Low Sperm count, Poor progressive motility of sperms and Gross morphological abnormalities.
• Azoospermia, sperms are retrieved from Epididymus by MESA or PESA, or from Testes by TESE.
• It is also done when numbers of ova retrieved are low to give the best chances to fertilize.
• Spermatozoa sometimes fail to fertilize ova in conventional IVF procedure.