Intracytoplasmic sperm injection (ICSI /ˈɪksi/ IK-see) is an in vitro fertilization (IVF) procedure in which a single sperm cell is injected directly into the cytoplasm of an egg. This technique is used in order to prepare the gametes for the obtention of embryos that may be transferred to a maternal uterus. With this method, the acrosome reaction is skipped. The first human pregnancy generated by ICSI was carried out in 1991 by Gianpiero Palermo and his team.