Intracytoplasmic sperm injection, or ICSI, is a form of in vitro fertilization in which fertilization occurs outside of the body. First, egg cells are harvested and transferred to a special media in a laboratory dish. Within a few hours, a single sperm is injected through a fine needle into the center of an egg cell to aid in the process of fertilization. If successful, the cell will divide and form the beginning stages of an embryo. If necessary, the DNA of a single cell from an embryo may be checked to ensure that various genetic disorders are not present. Typically, several egg cells are harvested and fertilized at the same time then inserted back into the uterus to increase the chances that one will implant and develop into a successful pregnancy.