It is a technique where a live sperm is injected directly in to oocyte thereby bypassing the limitation imposed by the sperm mobility and other sperm factors in binding with the oocyte. Fertilization occurs when the sperm enters the cytoplasm of the egg and atier fertilization the egg becomes an embryo and grows in a laboratory for 1 to 5 days before it is transferred into women's Uterus. ICSI fertilizes 50 % to 80%.
- Intracytoplasmic Morphologically Selected Sperm Injection, more commonly referred to as IMSI is an assisted reproductive technique used to fertilise eggs in the IVF lab, when sperm defects are the cause of the infertility.
- In IMSI, the sperm sample is examined using an inverted microscope, to check for defects within the sperm head, as well as shape, size and motility abnormalities. This digitally enhanced microscope provides a much greater magnifying power (about 6000x magnification) compared to the one normally used in ICSI (200x). The embryologist selects healthy sperm from the sample, which is then injected into the inner part of the egg. Once it results in fertilization, the embryo is implanted into the aspiring mother's womb. However, since this is a selection process, it might not be suited to men with a very low sperm count.