Intracytoplasmic sperm injection (ICSI)
Intracytoplasmic sperm injection (ICSI)
Methods of assisted reproduction are the solutions for couples which have problem to conceive. One of them is intracytoplasmic sperm injection (ICSI). It is the method in which is pre-collected sperm injected directly into an egg. This method is recommended for couples in which is the penetration of sperms into the egg problematic part of the conception. ICSI is most commonly used in men with unsatisfactory sperm count. Sperm count is a microscopic examination of the semen in which is the quality and quantity of sperm assessed. Thanks to ICSI method was the amount of couples which would have had to use donated sperms reduced.
Fertilization is a complex process for which success is proper functioning reproductive system of woman essential. The eggs matures under the influence of sex hormones in the ovaries. These hormones are follicle stimulating hormone (FSH) and luteinizing hormone (LH). Within the maturation of eggs in the ovaries are more sex hormones produced, i.e. oestrogens. The function of oestrogen is to enhance the growth and maturation of eggs and also to prepare the uterus for the nidation of embryo. After the egg is matured, it is released from the ovary and picked-up in fallopian tube. This phase is called ovulation. Afterwards, the egg moves through fallopian tube toward the uterus. Ideally, the egg comes in contact with sperms, i.e. male sex cells, in the fallopian tubes and fertilization occurs. The sperms are erected into the genital tract of the women in ejaculation during sexual intercourse. One of sperms, the fastest, penetrates into the egg and the genetic information for new individual is complete. Therefore, cell proliferation, i.e. cleavage, can begin. Five days after fertilization, the embryo reaches the uterus in which is it awaited with rich grown uterine lining. In the uterus is the embryo nidated and begins to grow. If an error occurs in any part of the complex fertilization process, the reproductive disorders develop. As already mentioned, ICSI is mainly used in the men whose sperms have difficulty with the penetration of egg packaging, and thus to give possibility to development of offspring.
Retrieval of eggs and sperms for ICSI
The first step in the intracytoplasmic sperm injection (ICSI) is the decision about which way is the best to retrieve matured egg. Woman may be hormonally stimulated to induce the larger number of eggs which will be matured in the ovaries. If the woman is healthy, it is possible to let the egg to mature naturally in the ovary and remove it at the time of ovulation. The woman is carefully monitored during the ovulatory cycle and according to the levels of FSH and LH is the exact time of ovulation determined. The egg retrieval is performed under general anesthesia. Ultrasound probe is introduced into the vagina which allows the doctor to see where is the ovary and egg located by use of special displaying option. Afterwards, a puncture is made through the vaginal wall with a long needle and the egg is aspirated into the needle. The woman rests about two hours in cot after intervention and then, if everything is in order, she can go home. The collection of partner 's semen is required in preparation for this process. This can be performed in two ways. The first one is to obtain sperms by masturbation after at least 3 days of sexual inactivity. The second option is to retrieve the sperms by use of modern surgical method called MESA or TESE. MESA is a microsurgical technique in which are sperms removed from the epididymis, i.e. place where sperms accumulates. TESE is also the microsurgical method but only a small sample of testicular tissue in which are sperms produced is taken in this procedure. Both of these methods are performed under general anesthesia. Man rests for about two to three hours in cot after the intervention and then, if he feels comfortable enough, he can go accompanied home. Afterwards, from the semen sample is under the microscope selected single sperm that has the best qualities and therefore has the greatest chance to fertilize the collected egg.
Course of ICSI
If the sperm and eggs are removed, so-called intracytoplasmic sperm injection (ICSI) is performed. The entire process is done under the microscope. The egg is firmly held by the pipette. The one selected sperm is aspirated into very thin needle. Afterwards, the packaging of egg is punctured by thin needle and sperm is injected inside. The needle is carefully removed. The egg with injected sperm is let to incubate. This means that the egg is kept under conditions that simulate the environment in the woman's fallopian tube. We continuously monitor if it comes to fission of newly formed cell. If yes, it means success, therefore that we managed to create the embryo. When the fetus is large enough, it is introduced into the woman's uterus and we wait if it is nidated. If the fetus or embryo is properly nidated, nothing stands against the continuation of pregnancy.
Risks of ICSI
Before ICSI, it is necessary for the couple to be genetically tested since the natural selection of sperms is suppressed, thus it does not come to natural exclusion of defective sperms which is done genetically. Therefore, it is necessary to exclude diseases that might be transmitted into the genetic makeup of the fetus. Sometimes, preimplantation genetic diagnosis is performed. It is a genetic test of one or two embryotic cells which is done to exclude genetic mutations. This allows the transfer of embryo from which is the healthy offspring most likely to be born. Other risks are ectopic pregnancy, multiple pregnancy, bleeding during the retrieval of eggs, the infection after egg retrieval or ovarian hyperstimulation syndrome, i.e. response of female organism to high doses of hormones. Therefore, the woman is during hormonal stimulation intensively monitored. It is essential to inform the doctor who is able to deal with the given situation about any difficulty or doubts.