Intracytoplasmic sperm injection (ICSI)
Intracytoplasmic sperm injection (ICSI) is a new procedure that allows couples with sperm problems to have IVF fertility treatment. Developed in Belgium in 1992, ICSI is the process of injecting a single sperm into an egg. It is a remarkable procedure since it allows men with only very few sperm to have a chance of having their own children.

What is the normal process of fertilization during an IVF cycle?
The eggs that are collected from your ovaries are kept in special incubators in the IVF laboratory. The sperm sample is processed to recover the strongest and best swimming sperm to be used to inseminate the eggs. Poorly swimming and dead sperm are discarded as medical waste. Because the egg has a thick shell and is surrounded by thousands of follicle cells, the Embryologist will usually add about 100,000 sperm to each egg. Adding so many good sperm to each egg disperses the follicle cells and usually ensures that one sperm will get in to fertilize the egg.

Figure 2. A human egg surrounded by sperm.

Will my sperm be able to fertilize our eggs?
All couples having IVF fertility treatment will have their sperm sample analyzed by the laboratory staff. As well as checking the basic parameters of the sperm sample, such as count and motility, the laboratory will examine how well the sperm are swimming and whether or not the sperm are physically normal. It is important that the sperm are strong swimmers and that they are the correct shape to be able to reach and penetrate the egg. In general, men with "normal" sperm samples have nothing to worry about and do not need ICSI. However, if we think that you need ICSI we will talk to you after we examine your sperm sample. Any man that has had consistently poor sperm samples, and men that need to have their sperm recovered surgically will always need ICSI.

What does ICSI involve?
If a decision has been made by you and your physician to have ICSI, the laboratory will get specific instructions on how many eggs to inject. Sometimes, couples with borderline sperm samples will decide to have some eggs injected and some inseminated normally.

In the laboratory, the follicle cells are removed from around each egg with an enzyme solution. One by one, the naked eggs are held by gentle suction in a glass holding pipette, and a single sperm is injected. The tiny glass needle containing the sperm is gently pushed through the shell of the egg and the sperm is deposited in the egg cytoplasm.

Figure 3. The process of ICSI:

1. Suction applied by a glass holding pipette keeps the egg from moving during the injection. A single sperm is picked up in a tiny microneedle.

2. The needle has a sharp tip and can be gently pushed through the shell of the egg and into the cytoplasm

3. The sperm is deposited deep inside the egg and the empty needle is withdrawn.

Click here to view laboratory footage of an ICSI.

Is ICSI a safe procedure?
ICSI is different from conventional insemination since we clean away the follicle cells from around the eggs and an embryologist chooses the sperm to be injected. A small number of eggs do not tolerate the injection procedure and you can expect that about 5% of eggs die as a direct result of ICSI. However, fertilization rates, embryo quality and pregnancy rates are the same as for couples who do not have ICSI.

It is important for you to be aware that ICSI may have some risks for resulting children also. Studies published in scientific journals have shown that children resulting from ICSI are more likely than other children to have a genetic abnormality. The risk of such an abnormality is usually 2 children per 1000 births, but with ICSI the risk is 8 children per 1000 births. The problems seen in the affected children can be very serious (e.g. heart defects) so your physician will talk to you in detail about your risks before committing to the ICSI procedure.

Who can I talk to if I have further questions about ICSI and IVF treatment?
If you think that you might need ICSI during your IVF cycle, your physician will explain the procedure and the risks. Pacific Fertility Center’s staff features some of the leading infertility specialists in ICSI and IVF fertility treatment in Northern California’s San Francisco Bay Area and throughout the United States. Our infertility specialists are familiar with the scientific literature and can give you the latest information regarding ICSI fertility treatment and your IVF cycle. We encourage you to ask questions and you can speak to a member of our fertility clinic staff by phone at any time.