Intracytoplasmic sperm injection - ICSI and IVF

May 1, 2008

What is ICSI?

ICSI is an acronym for intracytoplasmic sperm injection - which is a long, fancy way of saying “inject sperm into the middle of the egg”. ICSI is a very effective method to get fertilization of eggs in the IVF lab after they have been retrieved from the female partner. IVF with ICSI involves the use of specialized micromanipulation tools and equipment and inverted microscopes that enable embryologists to select and then pick up individual sperms in a tiny specially designed hollow ICSI needle. Then the needle is carefully advanced through the outer shell of the egg and egg membrane and the sperm is then injected into the inner part (cytoplasm) of the egg. This will usually result in normal fertilization in approximately 70-85% of eggs injected with viable sperm. First, the woman must be stimulated with medications and have an egg retrieval procedure so that we can obtain several eggs in order to attempt in vitro fertilization and ICSI.

See a series of images demonstrating the ICSI technique

Who should be treated with intracytoplasmic sperm injection?

There is no “standard of care” in this field of medicine regarding which cases should have the ICSI procedure and which should not. Some clinics use it only for severe male factor infertility, and some use it on every case. The large majority of IVF clinics are somewhere in the middle of these 2 extremes. Our thinking has changed over time - we are now doing more ICSI (as a percentage of total cases) than in the past. Certainly, as we learn more about ways that we can help couples conceive, our thinking in this area will continue to evolve. Having said that, we are currently recommending in vitro fertilization (IVF) with ICSI for:

1. All couples with severe male factor infertility that do not want donor sperm insemination.

2. All couples with infertility with:

Sperm concentrations of less than 15-20 million per milliliter
OR
Sperm motility less than 35%
OR
Very poor sperm morphology (subjective - specific cutoff value is not appropriate)

3. All couples having IVF who have had a previous cycle with no fertilization - or a low rate of fertilization (low percentage of mature eggs that are normally fertilized).

4. All couples having IVF who have a very low yield of eggs at the egg retrieval - our current cutoff is 5-6 (or less) eggs. In this scenario, ICSI is being used to try to get a higher percentage of eggs fertilized than with conventional insemination of the eggs (just mixing eggs and sperm together).

How is ICSI performed?

1. The mature egg is held with a specialized holding pipette.

2. A very delicate, sharp and hollow needle is used to immobilize and pick up a single sperm.

3. This needle is then carefully inserted through the zona (shell of egg) and in to the cytoplasm of the egg.

4. The sperm is injected in to the cytoplasm and the needle carefully removed.

5. The eggs are checked the next morning for evidence of normal fertilization.

Fertilization and pregnancy success rates with ICSI

Fertilization rates for ICSI: Most IVF programs see that about 70-85% of eggs injected using ICSI become fertilized. We call this the fertilization rate, which is different from the pregnancy rate.

Pregnancy success rates for in vitro fertilization procedures with ICSI have been shown in some studies to be higher than for IVF without ICSI. This is because in many of the cases needing ICSI the female is relatively young and fertile (good egg quantity and quality) as compared to some of the women having IVF for reasons other than male factor infertility. Another way to say this is - average egg quantity and quality is usually better in ICSI cases (male factor cases) because it is less likely that there is a problem with the eggs - as compared to cases with unexplained infertility in which there is more probability of a somewhat reduced egg quantity and quality (on the average, since some women in this group have egg related issues).

ICSI success rates vary according to the specifics of the individual case, the ICSI technique used, the skill of the individual performing the procedure, the overall quality of the laboratory, the quality of the eggs, and the embryo transfer skills of the infertility specialist physician performing the procedure.

Sometimes IVF with ICSI is done for “egg factor” cases - low ovarian reserve situations. This is when there is either a low number of eggs, or lower “quality” eggs (or often both). In such cases, ICSI fertilization and pregnancy success rates are somewhat lower (as a group) since the main determinant of IVF success is the quality of the transferred embryos - and the quality of the eggs is the most crucial factor determining the quality and viability of the resulting embryo.

In some cases, assisted hatching might be done on the embryos prior to transfer, in order to maximize chances for pregnancy.

Our IVF pregnancy success rates

See a general discussion about IVF pregnancy success rates

Cost of IVF with ICSI

See the IVF pricing page for details regarding the cost of ICSI at our IVF clinic. Both costs and pregnancy success rates can vary greatly between different IVF clinics.