ICSI is a procedure that involves injecting a sperm into the cytoplasm of the egg and thus performing fertilization. The main difference from the standard in vitro procedure is in the laboratory stage. In classical in vitro fertilization, the egg is inseminated in a special petri dish with thousands of the partner’s sperm. In the ICSI procedure, an experienced embryologist releases the eggs from the surrounding cells with the help of the enzyme hyaliponidase. Immobilization and capture of a suitable spermatozoon through the so-called injection pipette, fixation on the egg c so-called. holding a pipette and injecting the spermatozoa into the cytoplasm of the ovum. The manipulation is performed with the help of a special technique / micromanipulator / under microscopic control, at a magnification of 200-400 times, with the size of the working surface of the pipette 20 times (at the holding pipette). The injected spermatozoon of the ovum is returned to the incubator and 16-18 hours later it is considered that there is fertilization. The zygotes thus obtained do not differ in any way from those fertilized by IVF. The embryos are placed in a special medium in an incubator, which maintains the suitable conditions for cultivation / 370C temperature, controlled levels of CO2 and O2. Periodically, an assessment is made by a qualified embryologist, who assesses the development and quality of the embryos, and then proceeds with the transfer of the embryos, as in a standard IVF cycle.
In which cases may intracytoplasmic sperm injection be required?
ICSI technique is applied in the following cases:
- Decreased number of sperm in the ejaculate / Oligozoospermia /. This may be due to retrograde ejaculation or obstruction of the vas deferens (the tube through which sperm passes from the testicles);
- The complete absence of sperm in the ejaculate / Azoospermia / can be overcome if the production of sperm in the testicles is not disturbed. A puncture or biopsy of the testicle (Surgical extraction of sperm (TESE, TESA, MESA)) is performed, after which the obtained male gametes are injected into the cytoplasm of the egg;
- The presence of sperm with reduced motility and / or poor morphological assessment / Astheno-, Teratozoospermia / is also an indication for this type of assisted reproduction technique;
- Performed vasectomy, in which recovery cannot be successfully performed;
- ICSI is usually used in cases of cryopreservation of semen. When the right time comes, the frozen semen is thawed and the appropriate fertilization technique is applied;
- The presence of antibodies against sperm is also an indication for ICSI. They may be present in the man’s ejaculate or in the partner’s cervical secretions;
- Diagnosed poor biological survival of spermatozoa;
- Patients with few unsuccessful IVF cycles.
In recent years, the indications for the application of the existing procedure have been expanded, the method is also used for couples, in which the woman has advanced reproductive care, in the presence of endometriosis-based cybin infectility, an immunological factor, as well as in infertility with an unexplained outcome.
What is the difference between the invitro method and ICSI ?
Couples requiring ICSI fertilization go through the same procedure as those using IVF. In order to obtain the optimal number of eggs, the woman undergoes a hormonal course of treatment to stimulate the ovaries. Hormonal examinations and ultrasound examinations monitor the growing follicles in the ovaries. After the puncture of the follicles and the extraction of mature eggs.
The difference between the two methods is in the laboratory stage. Conducting ICSI versus IVF consists of directly injecting a single sperm into the egg. ICSI can also be performed with sperm obtained by puncture or testicular biopsy.
The advantage of ICSI is that it is an opportunity to treat severe infertility due to severe impairment of spermatogenesis, which would otherwise remain incurable. Experience has shown that the ICSI method requires the presence of a minimum number of motile, normal-shaped sperm. Theoretically, only a few sperm are needed to perform the procedure.