What is ICSI?

Intracytoplasmic Sperm Injection (ICSI) is a micromanipulation technique developed in the early 1990s in which a single, morphologically selected spermatozoon is injected directly into the cytoplasm of a mature oocyte. ICSI is performed by an embryologist using an inverted microscope equipped with micromanipulators, microinjection pipettes and a holding pipette.

The primary indications for ICSI include severe male-factor infertility (oligozoospermia, asthenozoospermia, teratozoospermia), the use of surgically retrieved sperm (TESA / TESE / MESA), prior fertilization failure with conventional IVF, and cycles that combine fertilization with preimplantation genetic testing where DNA contamination from supernumerary sperm must be avoided.

Fertilization rates following ICSI typically range between 60% and 80% per mature oocyte, although clinical pregnancy and live-birth rates depend on a broader set of factors including oocyte quality, female age, endometrial receptivity and laboratory quality control. ICSI itself does not improve embryo quality beyond what the gametes can biologically support; it merely bypasses a fertilization barrier.

Use of ICSI is regulated locally and must be performed in licensed embryology laboratories. WFA member institutions that offer ICSI report on their service scope on their member detail pages.