Intracytoplasmic Sperm Injection
Intracytoplasmic sperm injection (ICSI) is a form of in vitro fertilization, but with fertilization occurring outside the body. It is usually required when sperm are too few for fertilization to occur through the incubation with an egg, which is the standard approach in IVF. For ICSI's initial step, 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. If successfully fertilized, the cell will divide and form the beginning stages of an embryo. The DNA of a single cell from an embryo may be checked for the presence of various genetic disorders. Typically, several egg cells are harvested and fertilized at the same time, then returned to the uterus to increase the chances of implantation and a successful pregnancy. The fertility specialist may recommend ICSI for moderate to severe male factor in which a man has few or no sperm in his ejaculate, but it is still possible to obtain viable sperm for ICSI using microscopic epididymal sperm aspiration and testicular sperm aspiration. Other indications for ICSI are unexplained infertility, failed fertilization, advanced age, and other, couple-specific situations.