Intra cytoplasmic sperm injection (ICSI) is a type of IVF (see section on IVF). This is a procedure used in specific circumstances during in vitro fertilization.

The main reason to perform ICSI is because of a low sperm count or poor sperm morphology (shape of the sperm). Other reasons include sperm obtained by epididymal or testes aspiration or biopsy, previous failed fertilization in conventional IVF, when performing PGD (pre-implantation genetic diagnosis), to reduce transmission of HIV or to increase fertilization rates.