Recent advance treatments
Intracytoplasmic Sperm Injection (ICSI) is a procedure in which an embryologist ‘assists’ a single sperm to ‘merge’ with the egg. It only takes one sperm to fertilise the egg, the embryologist catches a single sperm and injects it directly into the egg. This technique is useful for male infertility.
Who should use ICSI?
ICSI is suitable for patients who have:
- Low sperm count and mobility
- Abnormally shaped sperms
- Sperm obtained via testicular biopsy or micro TESE
- Low fertilization rates with standard IVF
ICSI IVF should only be used by couples having above mentioned problems. It is recommended that couples who have success with standard IVF should not opt for this technique. ICSI can be performed with fresh or frozen sperm.
The process for ICSI IVF is same as a standard IVF. The only difference is the way the egg is fertilised.
Sperm Selection Process
Healthy sperms have a certain shape and size, notably an oval head and a long tail which they use to push themselves as they swim. Infertile men make fewer such sperms. Hence, sperm selection is very important for ICSI.
Another important factor is sperm motility. A sperm’s motility is its ability to move itself around and penetrate an egg. This is influenced by the length and size of its tail. Curly tails or doubled up tails are not very efficient.
As a routine, a small amount of washed and prepared sperm is placed in thick viscous media that slows the sperm down and a sperm is selected from this based on shape, mobility and trajectory. The most “healthy” sperms are selected and immobilized by squashing their tails with a glass injection needle. One of these sperms is then sucked into a needle and injected in an egg.
How is ICSI done?
The egg is placed in customized dishes under a microscope and positioned using a leading micro-manipulator. A holding pipette secures the mature egg. Then, a thin, sharp glass micropipette, loaded with a single sperm, is pushed through the zona pellucida (outer egg casing) and then the oolemma (cell membrane of the egg) to enter the centre of the egg. The sperm is carefully deposited here.
Here, the sperm does not have to do any of the work of swimming to the egg and penetrating. Now, all they have to do is fertilise the egg.
Once the procedure is complete, the egg is kept in an incubator and checked the next day for fertilisation.
ICSI is more invasive compared to standard IVF. Hence, there is a slim chance (less than 2%) that the egg may be damaged resulting in a non-viable egg.
What is Intracytoplasmic morphologically selected sperm injection (IMSI)?
IMSI is the technique used to select the best sperm with the help of high-magnification digital imaging microscope for microinjectionn into the egg.
This process helps eliminate sperms with potential abnormalities for available eggs.
Why perform IMSI?
IMSI is particularly useful for males who have a high number of abnormal sperms and previous poor outcomes in IVF with ICSI. This technique helps to increase the chances of fertilisation and healthy embryos for implantation.
The sperms which are identified as normal are used in the fertilisation procedure by ICSI method.
Who is suitable for IMSI?
- very low numbers of sperm
- a high proportion of abnormally shaped sperm
- poor outcomes with previous ICSI treatments