ICSI is beneficial for couples with infertility due to severe male factor issues such as:
- poor sperm motility, or movement (less than 10 percent motile)
- abnormal morphology, or shape
- oligospermia (very low sperm count)
- azoospermia (zero sperm count) due to either vasectomy or other obstructions, or because of problems with sperm production
If preliminary semen analysis indicates that ICSI is a necessary and appropriate treatment, the couple will prepare for IVF [page link]. Instead of mixing the eggs retrieved from the woman with the man's sperm in a glass dish (as in standard IVF, without ICSI), a single sperm cell is injected via a special glass needle called a pipette into an egg cell. At that point, about two thirds of these sperm-injected eggs will fertilize and start developing toward embryo stage.
Embryos created with ICSI also undergo a procedure known as assisted hatching before being transferred to the woman's uterus. In assisted hatching, a lab procedure using chemicals or lasers dissolves an embryo surface to improve the likelihood of implantation. Embryo transfer usually occurs around three to five days after oocyte retrieval. Good quality embryos that are not transferred at that time can be cryopreserved, or frozen, for later attempts at pregnancy.
ICSI has been used since the early 1990's, and preliminary studies on the children born as a result of ICSI do not suggest an increase in congenital abnormalities. However, children conceived through IVF with ICSI for reasons of male factor infertility may be more likely to inherit certain genetic conditions. Also, some egg cells are irreparably damaged by the ICSI process.
