In situations where the number or quality of sperm is insufficient to allow fertilization in a dish, individual sperm may be injected into eggs by means of intracytoplasmic sperm injection (ICSI). The use of ICSI has expanded the application of in vitro fertilization (IVF) to include serious male subfertility, previously untreatable by other means.
ICSI may be performed with ejaculated sperm or with sperm that have been retrieved from a man’s testicles by a minor surgical procedure performed by a urologist .
Whereas several hundred thousand sperm are required for standard insemination in a petri dish, only one sperm per egg is required for ICSI. The sperm used for ICSI may be retrieved on the day of the egg retrieval. Alternatively, frozen sperm obtained from previous collection procedures may be used.
In addition to those situations where the number of sperm is low, ICSI is also used when the quality of sperm is sub-optimal. Common examples include problems with sperm movement (motility) or sperm structure (morphology). These sperm characteristics may be recognized on standard semen analysis testing.
Further indications for ICSI may be discovered by means of more technical sperm evaluations. We also consider ICSI in cases of poor fertilization during prior IVF attempts and when a low number of eggs are retrieved.