Intracytoplasmic sperm injection (ICSI) is an assisted reproductive technology used to treat sperm-related infertility. In the laboratory, a single sperm is injected into an egg; after 2 to 5 days, one or several of the fertilized embryos are transferred to the woman's uterus or fallopian tube.

Any embryos that implant in the uterus may result in pregnancy and birth of one or more infants.