ICSI – intracytoplasmic sperm injection.
Unlike IVF, this method involves selecting a single sperm and injecting it directly into the egg.
What is behind the terms IVF and ICSI?
ICSI at a glance
IVF and ICSI compared
When is ICSI the method of choice?
Intracytoplasmic sperm injection is indicated when reduced semen quality in the male partner is the cause of involuntary childlessness. If the sperm count is too low, motility is impaired and/or the proportion of malformed sperm is increased, fertilisation the "natural" way is not possible and therefore has to be assisted by micro-injection.
30–40 percent per cycle
The chance of becoming pregnant with the help of ICSI treatment is 30–40 percent per cycle – depending on the age of the couple, the hormonal baseline, underlying conditions (diabetes mellitus, high blood pressure, etc.) and lifestyle factors (excess weight, stress, nicotine use, excessive alcohol consumption, etc.).
How ICSI treatment works.
From hormonal stimulation to the implantation phase – the seven steps of ICSI treatment.
Hormonal stimulation of the ovaries
With only a few exceptions, IVF (in vitro fertilisation) or ICSI (intracytoplasmic sperm injection) treatment is carried out after hormonal stimulation of the ovaries. The aim of hormone therapy is to allow several follicles to mature simultaneously on both ovaries in order to obtain several eggs capable of fertilisation.
A preparatory phase ("down regulation") tunes the body for the actual stimulation by suppressing the body's own hormone production and release. This can be done via daily injections under the skin (subcutaneous) or by taking certain medications orally – with the advantage that the stimulation phase becomes easier to control externally.
For the subsequent stimulation of the ovaries, FSH (follicle-stimulating hormone) and LH (luteinising hormone) are used in pure form or as a combination preparation. During hormone treatment, a specific amount of these hormones (depending on age, weight, etc.) is injected subcutaneously every day, always at the same time of day. The technique is explained and demonstrated in detail at the start of treatment and can be carried out by the patient herself or by her partner – daily visits to the doctor are not necessary.
Close ultrasound monitoring allows the number of follicles, their growth and the build-up of the uterine lining to be observed precisely. Once the follicles have reached a certain size, ovulation is triggered with the hormone hCG (human chorionic gonadotropin). This makes it possible to determine the optimal time for egg retrieval, shortly before ovulation.
Egg retrieval
36 hours after the "trigger injection", the eggs are retrieved transvaginally (through the vagina) under ultrasound guidance. Using a needle, the follicles are located under ultrasound view, punctured, and the follicular fluid together with the egg it contains is aspirated. The eggs are then isolated from this fluid under the microscope, transferred to a special culture medium and incubated at 37 °C.
Follicle puncture takes 5–15 minutes on average, depending on the number of follicles. To make the procedure easier, our patients receive a combination of sedatives and painkillers. The follicle puncture is performed on an outpatient basis – all that is required is an observation period of 1 to 2 hours in our recovery rooms.
Sperm collection
The sperm sample is collected by masturbation after 2–3 days of abstinence (no ejaculation) on the day of egg retrieval. This is not always easy "on command" or under time pressure and stress – so in exceptional cases the sample can also be brought from home. Please note that the time between collecting the sample and handing it in at the institute must not exceed two hours.
Fertilisation – the ICSI method
The retrieved eggs are fertilised on the same day. The principle of the ICSI method is that the fertilisation process is "imitated" by micromanipulation under a special microscope: the egg is held in place with a glass pipette, and a sperm is inserted directly into the egg with a fine hollow needle.
The next day, it is checked under the microscope how many of the eggs actually show signs of fertilisation (two pronuclei and two polar bodies).
Embryo transfer
2–5 days after fertilisation, 2–3 embryos are placed into the uterus under ultrasound guidance using a thin, flexible plastic tube (catheter).
The day on which the embryo transfer takes place depends on the number of fertilised eggs. If 1–4 eggs have been fertilised, they are usually returned to the uterus 2–3 days after the puncture. During this time, the embryos are observed daily as they develop (cell division) and assessed according to criteria such as cell division rate and regularity of cell division. The embryos of the best quality are selected for transfer.
With five or more embryos, a transfer on day 5 after fertilisation is aimed for – a so-called blastocyst transfer. The blastocyst is the most advanced embryonic stage that can be achieved outside the body. If there are more good-quality embryos than intended for transfer, these can be cryopreserved (frozen in liquid nitrogen).
Placing the embryos takes only a few minutes and is generally painless. Afterwards, we recommend that our patients relax for 20–30 minutes in our recovery rooms.
Assisted Laser Hatching (ALH) – help with "hatching"
The egg or embryo is surrounded by a firm shell, the so-called zona pellucida. When the embryo reaches the blastocyst stage in the course of its development, it must hatch out of this shell in order to implant in the uterus. Sometimes, however, this shell is "hardened" or unusually thick, which makes implantation difficult or even impossible. In these cases, the zona pellucida is scored or thinned using a laser to make it easier – or possible at all – for the growing embryo to "hatch" and thus to implant.
Implantation phase (luteal phase)
Egg retrieval marks the start of the second half of the cycle, the so-called luteal phase. In this phase, the body's own production of the corpus luteum hormone is supported with medication, preparing the uterine lining (endometrium) optimally for the implantation of the embryo. The medications used in the luteal phase can be administered as intramuscular depot injections, subcutaneous injections, tablets or vaginal suppositories.
Two weeks after fertilisation of the eggs, a pregnancy can be detected at the earliest by measuring the pregnancy hormone hCG in blood or urine. If a pregnancy is confirmed, luteal phase support is continued until the 12th week of pregnancy.
Frequently asked questions about ICSI.
What is the difference between ICSI and IVF?
With IVF, several hundred thousand prepared sperm are added to each egg, and the sperm finds its own way into the egg. With ICSI, a single sperm is selected and placed directly into the egg with a fine hollow needle. ICSI is therefore the method of choice when semen quality is not sufficient for fertilisation the "natural" way. Stimulation, egg retrieval, embryo transfer and implantation phase proceed the same way with both methods.
When is ICSI recommended?
When a reduced semen analysis is the cause of the involuntary childlessness: with too low a sperm count, impaired motility or an increased proportion of malformed sperm. ICSI is also frequently the next step after a previous treatment in which noticeably few eggs were fertilised. The basis of the decision is always a current semen analysis.
How long does an ICSI treatment take?
An ICSI cycle corresponds in its duration roughly to a monthly cycle: around two weeks of hormonal stimulation, then the egg retrieval, a few days later the embryo transfer, and then about two weeks of waiting until the pregnancy test. Daily visits to the doctor are not needed – for the ultrasound and hormone checks, you come to us briefly several times.
What are the chances – and what role does age play?
The most important influencing factor is the age of the woman, because the number and quality of the eggs decline over the years. Added to this are the hormonal baseline, underlying conditions such as diabetes mellitus or high blood pressure, and lifestyle factors such as excess weight, stress, nicotine and excessive alcohol consumption. How your personal starting position is to be assessed is something we discuss on the basis of your findings – it can only be answered seriously on an individual basis.
Does ICSI carry additional risks for the child?
ICSI has been established for decades – the Wunschbaby Institut Feichtinger introduced it in Austria in 1993, and worldwide a great many children have been born after ICSI since then. With severely reduced semen quality, a genetic cause can lie behind it that becomes relevant in the course of treatment; in such cases we discuss a genetic work-up, which we can carry out in our own genetics laboratory. We inform you about all points in detail before treatment begins.
What risks and side effects does the treatment have for the woman?
The hormonal stimulation can cause a feeling of tension in the lower abdomen and mood swings; in rare cases, overstimulation of the ovaries occurs. That is why we monitor closely by ultrasound and dose individually. The egg retrieval is a short outpatient procedure under sedatives and painkillers, in which, as with any procedure, rare complications are possible. If several embryos are transferred, the probability of a multiple pregnancy increases.
Can the sperm selection for ICSI be improved?
Yes. Because a single sperm is selected for ICSI, this selection plays a special role. With PICSI we use the binding of mature sperm to hyaluronic acid, and with the Fertile Chip© ("Chipsi") a microstructure that imitates the natural migration of the sperm. Whether such a procedure makes sense in your case depends on the semen analysis and on the course of previous treatments.
What does an ICSI cost and what does the IVF Fund cover?
In Austria, the IVF Fund can cover part of the costs of an IVF or ICSI treatment, provided certain medical and personal requirements are met – these include, among other things, the indication and age limits. The Wunschbaby Institut Feichtinger has had a contract with the IVF Fund since the year 2000. Whether a cost contribution is possible for you and what your own share will be is something we check together with you in advance – transparently and before you decide.
„Ich bin so überglücklich ich hatte 16j Kinderwunsch und beim 1 mal hat es sofort geklappt jetzt haben wir eine wunderschöne Tochter 4 Monate. Ich bin so dankbar“
Even more precise sperm selection
With PICSI and the Fertile Chip© ("Chipsi") we offer modern methods to select the optimal sperm for ICSI.
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