Intracytoplasmic sperm injection, or ICSI, is a form of in vitro fertilization. That means the egg is fertilized outside the body. First, egg cells are harvested. Then they're placed in a special media in a laboratory dish.
Within a few hours, a sperm is injected through a fine needle into the center of an egg. If successful, the cell will divide and form the first stages of an embryo.
Typically, several eggs are harvested and fertilized at the same time. Then they're placed in the uterus. This increases the chance one will implant and become a successful pregnancy.
Review Date 1/10/2022
Updated by: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.