Intracytoplasmic Morphologically Sperm Injection (IMSI)
The sperm is selected under a high power light microscope (enhanced by digital imaging) to magnify the sperm sample over 6000 times. With this microscope we can see the internal morphology of the sperm and discard those with abnormalities. According to the WHO a mature sperm should ideally have an oval head with a length of between 4 and 5 microns and a width between 2.5 and 3.5 microns. One healthy sperm is injected into each egg.
IMSI may improve the chances of in vitro fertilization and can be used after several unsuccessful IVFs.