ICSI: Intracytoplasmic Sperm Injection
ICSI, short for intracytoplasmic sperm injection, is a special form of in vitro fertilization. It is used when there are too few motile sperm cells in the man’s ejaculate to fertilize the egg naturally. Here you can find out exactly how ICSI works, when it is indicated, what it costs and what opportunities and risks the procedure entails.
Why perform an intracytoplasmic sperm injection (ICSI)?
When the desire to have a child naturally remains unfulfilled for a long time, many couples opt for artificial insemination. One of the most commonly used assisted reproduction methods is in vitro fertilization (IVF) . It differs from the more commonly used insemination, since the fertilization of the egg takes place outside the female body and is then injected into the uterus after fertilization. However, if the man’s ejaculate does not contain enough sperm to fertilize an egg cell without help, a special form of IVF, ICSI (intracytoplasmic sperm injection), is often used.
In which cases is an ICSI performed?
In 40% of involuntarily childless couples, the cause of infertility lies with the man . One reason for this may be that the man’s sperm quality is too poor to fertilize the woman naturally. This means that the sperm in the ejaculate are not mobile enough, have defective shapes or are simply too few. For a normal IVF, the doctor performing the procedure needs between 50,000 and 100,000 healthy and functioning sperm per egg. If the number of motile sperm cells in the ejaculate is less than one million, normal IVF is no longer considered promising. The man’s sperm must then be “helped” with another method in fertilizing the egg cell: ICSI.
How does intracytoplasmic sperm injection work?
The process of ICSI basically corresponds to that of normal IVF. Only the type of actual fertilization of the egg differs fundamentally in ICSI. Before the actual fertilization, ICSI requires thorough preparation by both partners:
- Preparing women for ICSI : Women are treated with hormone treatmentretrieved several oocytes. For this purpose, the administration of special hormone preparations regulates the cycle between the 18th and 22nd day to such an extent that ovulation is prevented for the time being. It usually takes about two weeks before the cycle is completely broken and the treatment can move on to the next phase. This is followed by hormone stimulation, which causes the ovaries to produce more follicles. Further hormone injections promote their growth. When after about a week about 5 to 15 of these follicles have grown to the correct size, the administration of the hormone HCG starts ovulation and the egg cells are thus prepared for fertilization. Before actual ovulation occurs
- Preparing the man for ICSI : Before the procedure, a semen analysis is carried out on the man to determine the sperm quality – the so-called spermiogram. The sperm is then washed in the centrifuge together with a special nutrient solution, and a suitable sperm for fertilization is selected for each egg cell in the laboratory. As a rule, a blood test is also carried out on the man before the procedure in order to be able to rule out hereditary diseases and thus prevent any defects from being passed on to the child. If the man’s ejaculate does not contain any sperm at all, i.e. he suffers from azoospermia, the sperm cells must be obtained directly from the epididymis or testicles by means of a microsurgical procedure. With the so-called MESA, the semen is taken directly from the vas deferens, with the TESE, sperm cells are extracted from the tissue of the testicles.
Finally, when the ovum is fertilized by ICSI, there is a fundamental difference to conventional IVF:
- While in IVF several tens of thousands of sperm cells are placed in a Petri dish together with an egg cell and fertilization is hoped for, in ICSI the egg cell is specifically fertilized with just a single sperm cell. For this purpose, the previously selected sperm cell is injected directly into the cytoplasm of the egg cell in the ICSI procedure. For this purpose, the egg cell is fixed under the microscope and a single seminal thread is injected into the cell nucleus using a thin needle. In this way, the egg cell is “forced” to be fertilized by a single seminal thread.
Then it continues as with normal IVF:
- Within the next 18 hours, the embryologist can determine whether the egg cell has actually been fertilized. If this is the case and after 24 to 72 hours there is growth of the embryo, the return of the fertilized egg to the woman’s body can be carried out. This transfer is again the same as with normal IVF. The eggs are injected directly into the uterus through a flexible tube so that they can implant there.
Chances of success of an ICSI
Unless male infertility is particularly severe, ICSI offers no better chance of success than conventional IVF. The percentage of fertilized eggs and pregnancies is about the same for the two methods. However, since ICSI is more complicated and expensive than conventional IVF, the special ICSI treatment is only worthwhile for couples whose male fertility is particularly severely limited or for whom previous IVF has already failed because the egg cells were not sufficiently fertilized could become. In addition, the probability of success of ICSI decreases with increasing age of the woman.
How much does intracytoplasmic sperm injection cost?
The costs of ICSI vary from practice to practice, but total around 5,000 euros or more. As a rule, the statutory health insurance companies cover half of the costs for up to three ICSI treatments. However, this only applies to married couples, unmarried partners must bear the full costs themselves. In the case of privately insured persons, the support depends on whether the man who caused the injury is privately insured or not. If this is the case, the private insurance company will cover the entire costs of the ICSI. If only the woman is privately insured, but the man is legally insured, the private health insurance does not subsidize the treatment and the statutory health insurance only covers 50% of the man’s costs.
What are the risks of ICSI?
- Ectopic pregnancy: As with IVF, there is an increased risk of ectopic pregnancy with ICSI, although the egg does not have to pass through it in artificial insemination.
- Multiple pregnancies also occur much more frequently with ICSI than with natural conception, since artificial insemination by ICSI usually involves the transfer of three embryos into the uterus to increase the chances of nidation. Since implantation of all embryos is significantly higher in younger women, the number of embryos used in these is often reduced to two.
- Blood clots and kidney failure: In rare cases, hormonal overstimulation during artificial insemination can cause the blood vessels in the ovaries to become more permeable. This can result in water accumulating in the tissues or abdomen and the blood becoming thicker at the same time. The risk of blood clots increases and the poorer blood flow to the kidneys can limit their function or even lead to kidney failure.
Concerns about ICSI
Since ICSI has only been used since the early 1990s and is therefore a relatively new method, there are still no long-term studies on any malformations or clinical pictures that may occur that are directly related to ICSI. However, critics point out that the targeted selection of a sperm by humans prevents the natural selection by the egg cell. It is not known according to which principles the biological selection takes place and it is therefore also not clear whether important criteria are ignored when selecting the sperm cell.
Further information
You can find more information about ICSI and fertility medicine in our “ Infertility ” section.