In vitro fertilization may be supported by the use of intracytoplasmic sperm injection (ICSI) treatment, which was introduced at the beginning of the 1990s.

In particular, ICSI may be used if the quality of the sperm is poor or the sperm count is very low. In ICSI, a single sperm is retrieved from a washed sample and inserted into the egg by means of an ultra-fine pipette, using a microscope and equipment developed for the purpose. If necessary, sperm may be collected from the testicle or epididymis, or frozen sperm can be used. Otherwise the procedure is the same as for in vitro fertilization.