How is ICSI done?
Before ICSI can be done, mature eggs must be retrieved from the female partner
during a standard IVF cycle. The male partner’s semen sample is prepared in the
lab to isolate as many healthy moving sperm as possible.
Fresh ejaculated spermatozoa and frozen samples (that were surgically retrieved
from epididymis or testis) can be used and results in acceptable clinical
pregnancy rates.
In case no motile sperms are available, an attempt is made to elicit motility thus
verifying viability. Though the clinical, pregnancy and delivery rates in such
patients are halved.
After allowing the eggs to rest for 4-6 hours following their removal, the tight
outer coating of cells (cumulus) is removed from each egg. Only then can we be
sure the egg is mature enough to undergo ICSI.
Immature eggs cannot be injected. However, they can be incubated for a further
4-18 hours and reassessed. If they mature during that time and sperm is still
available, they can undergo delayed injection. Fertilization rates with delayed
injection are not as good as with usual ICSI techniques.
A special instrument is used to hold the egg in place. It is so small you can barely
see the tip with the naked eye. A thinner, sharp, needle-like instrument is used to
pick up a single normal appearing sperm. With great precision, the needle is
inserted through the egg’s outer coating (the zona pellucida) and into the egg
itself. The sperm is slowly injected into the egg, and the needle is removed,
leaving the sperm behind. The injected eggs are placed in an incubator overnight
and checked the next morning for signs of fertilization.