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Male Infertility and Assisted Reproductive Technologies
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Infertility, or sterility, represents significant problem of human reproduction. Per definition, if after one year of regular sexual intercourse, without contraceptives, there is no pregnancy, then it can be diagnosed infertility. It is considered that frequency of infertile couples in the world is around 10%-15%. It can be said that the problem of infertility has gone up slightly. Causes of infertility are numerous and various. Infertility has traditionally been thought of as a woman's problem. However, it is clear that frequency of infertility is approximately equally distributed between the sexes.

When infertility occurs, the partners are evaluated to determine the cause and best treatment choices. In the past, men with sterility had few options as a result of limited information about causes and even less information about successful treatment. But, new tests have made it possible to determine the causes of male infertility and treatments, and assisted reproductive techniques supply hope to many couples.

Treatment is conditioned by properly conducted diagnostic. In the past decade, there is done rapid progress in the diagnosis and treatment of female infertility. Medical therapy is not changed significantly, but there are improved surgical techniques, especially the introduction of microsurgery, in certain disorders significantly expanded therapeutic options, as well as their success. However, the most important effect is the introduction of methods of in vitro sperm processing and assisted reproduction in treatment of male infertility.

In treatment of male infertility, different methods of assisting reproduction can be used. Successful methods of assisted reproductive technologies are insemination into the uterus or fallopian tubes (IUI or ITI), in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and modification ICSI fertilization (PICSI). For serious cases of male sterility, it is necessary to use methods, such as ICSI and PICSI.

Infertility in men with reduced sperm concentration and normal motility, or normal sperm concentrations and slightly reduced mobility can be treated with IUI procedures or ITI.

Intrauterine and Intratubal Insemination (IUI and ITI)

Sperm must be taken into a sterile dish for about 2 hours before insemination. After liquefaction of ejaculate at room temperature, it must be determined number and motility of sperm. Preparation of sperm for insemination consists of removal of seminal fluid and cellular elements. This can be accomplished in two ways. One method is used to separate the sperm on certain density gradient. By centrifuging, as sediment remained moveable sperm, that must be separated and washed, until it receives 0.5 ml concentrated medium for insemination. Another method is the "swim-up" technique in which the ejaculate is diluted with medium and centrifuged. Current portion of suspension is removed, and the residue with the sperm is left in an incubator for 30 to 60 minutes. The top layer of the medium is movable sperm, the fraction separated and used for insemination.

Sperm must undergo the process of capacitation and acrosome reaction, to be ready to fertilize the egg. Capacitation is process of functional maturation of sperm cell, which includes the reorganization of the cell membrane surface, removing inhibitory factors, changes in cellular metabolism, the flow of ions and motility of sperm. Capacitation in vivo starts when sperm cells passes through the mucus of the cervix or in vitro during the processing of seeds in the medium. Changed physiological status of sperm and changes in sperm membrane prepares sperm to initiate functional acrosome reaction. Acrosome reaction occurs on the zone pellucida where the ZP3 protein is responsible for binding of sperm cell acrosome reaction and initiation. Acrosome reaction is a process that allows the dismissal acrosoms matrix which contains a number of enzymes (serine proteases acrosin, and other hydrolytic enzymes: hyaluronidase, neuraminidase, acid phosphatase and esterase), which enables sperm cell to penetrate the egg cell.

IUI or ITI is injecting isolated sperm through the catheter at the time of natural or induced ovulation in the uterus or fallopian tube.

In Vitro Fertilization (IVF)

IVF / ET (in vitro fertilization and embryo transfer) is a method of fertilization outside the body and transfer the embryo into the uterus. The first step in applying this method is the induction of folliculogenesis drugs. Events of induced menstrual cycle are monitored by ultrasound measurement of follicular diameter and daily determination of estradiol level in serum of patients. In women, the stimulation switch is happening when least two follicles are larger than 15 mm and estradiol levels in the serum increased above 1.3 nmol / l. Then, the injection of human chorionic gonadotropin is in the ovulatory dose (10 000 IU). Preparation of oocytes for fertilization, for medical assisted technology in the laboratory, begins by aspiration and isolation of follicles just before ovulation in spontaneous or stimulated cycle.

Intracytoplasmic Sperm Injection (ICSI)

If there is a question of the sperm's ability to fertilize the egg, because of either a low sperm count or poor quality of the sperm, it can be performed intra- cytoplasmic sperm injection instead of regular in vitro fertilization. With ICSI, the eggs are retrieved the same as with conventional IVF. The oocytes and the sperm are then fertilized in the laboratory. Then, a single sperm enters the egg cytoplasm.

Preparation of gametes

Oocyte must be exempt from cumulus oophorus, which for biologists represents a delicate job. For micro-fertilization must be used only mature oocytes. Sperm is obtained by ejaculation. If this is not possible, then the various procedures of biopsies are performed, usually testicular sperm aspiration (TESA) or extraction of sperm after testicular tissue biopsy (TESE). The mature egg is held with a specialized holding pipette. A really delicate, sharp needle is used to immobilize and pick up a single sperm. This needle is then carefully inserted in to the center (cytoplasm) of the egg. The eggs are checked the next morning for evidence. Three days later the resulting embryos are simply placed into uterus, just as with IVF.

PICSI

PICSI is a method of selecting the best possible sperm for fertilisation in the IVF protocol. PICSI is a modification of micromanipulation ICSI fertilization, which selects sperm according to how well they bind to the hyaluronan around an egg cell. PICSI is dish which is coated with drops of hyaluronan. Hyaluronan occurs naturally in substances that surrounds the oocyte, and participates in the process of linking the egg and sperm cell. This means that for fertilization used exclusively sperm cells which are capable of specifically binding to the egg layer. This ability has only mature sperm cell. Research shows that sperm that binds to hyaluronan has a lower probability of chromosomal abnormalities and higher DNA integrity.
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