Intracytoplasmic morphologically selected sperm injection, or IMSI, is the term used to describe the selection of a specific, high quality sperm cell for injection into the egg. The selection process takes advantage of the advanced in our ability to observe the sperm cells at a high level. Newer and higher resolution microscopy techniques have allowed the identification of an additional feature of a high quality sperm cell: the absence of large nuclear vacuoles.
These vacuoles, or bubbles, are found in the sperm’s head, and have been associated with abnormalities in the sperm’s genetic content, a quality that could lead to failed fertilization or early miscarriage. Therefore, it is believed that the pre-selection of sperm without severe head defects can improve the chances of IVF-ICSI success.
IMSI is recommended for patients who demonstrate a low percentage of normal morphology sperm in their semen, as well as couples with repeated failed IVF cycles.