ICSI – the acronym meaning IntraCytoplasmic Sperm Injection – is a procedure for fertilising an egg when the sperm counts are very low.
Confused patients often ask “What is the difference between ICSI and IVF?” BUT, these two treatments are exactly the same, EXCEPT for the method by which fertilisation is achieved.
In conventional IVF, the harvested eggs and sperm are mixed together in a Petri dish and incubated for a number of days. It is expected that the sperm will fertilise the eggs to produce embryos. However, this is assuming that the sperm are normal and active.
In ICSI, the egg is fertilised through the direct injection of a single sperm with the use of a fine needle. This makes ICSI the best procedure for patients with male factor infertility.
The steps for egg retrieval and sperm processing is the same as IVF cycle. Only the method of fertilization differs.
The embryologist uses a special instrument called the micro manipulator and picks up the mature egg with a holding pipette.
Immobilizes and picks up one sperm Using an injection pipette and inserts it into the egg to reach the cytoplasm.
Injects the sperm into the cytoplasm.
Withdraws the needle from the egg.
After ICSI, the fertilized eggs are monitored in the laboratory for signs of successful fertilization. Within five to six days, a healthy fertilized egg should divide into cells, forming a blastocyst.
An embryo transfer occurs either on the fifth or sixth day following the egg retrieval procedure or commonly the transfer is delayed and the embryos are frozen by a process called vitrification for future use .
ICSI is likely to be recommended in the following circumstances;
• When the man has a very low sperm count.
• A high percentage of abnormally shaped or slow sperm
• Previous vasectomy.
• A need to use frozen sperm that is not of the best quality.
• Problems with getting an erection and ejaculating.
• A complete absence of sperm in the ejaculate due to obstruction or defective sperm production
• esticular cancer patients with semen samples frozen prior to treatment.
• Severely decreased sperm motility, including totally immotile sperm.
Fertilization occurs when one of the sperm enters into the cytoplasm of the egg. In the ICSI process, a tiny needle, called a micropipette, is used to inject a single sperm into the center of the egg. With either traditional IVF or ICSI, once fertilization occurs, the fertilized egg (now called an embryo) grows in a laboratory for 1 to 5 days before it is transferred to the woman’s uterus (womb).
Once retrieved the semen sample is washed and a single sperm is isolated. This is then injected into an egg with a very fine hollow needle. Since the sperm is injected directly, it bypasses the need to swim through the cervical fluid. It can take a sperm up to 24 hours to fertilize an egg and create an embryo.
Very few sperms are sufficient as we use one sperm for one egg.
It is an expensive procedure requiring the use of specialised equipment.
Approximately 17-18 hours.The egg is placed back into the incubator. Fertilization occurs in 4-6 hours in humans but there are no visible signs until approximately 17-18 hours later. The first signs that fertilization have occurred visibly is the development of two round bodies in the center of the egg.