Intracytoplasmic sperm injection (ICSI) is an assisted reproductive technology used to treat certain infertility problems, such as 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 uterus or fallopian tube.

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