ART: ASSISTED REPRODUCTIVE TECHNOLOGY
If, for various reasons, couples are unable to have children, they rely on the methods summarized by the term "ART" (Assisted Reproductive Technology) as a possibility to fulfil their wish. These methods have in common that fertilization of the female oocyte is induced by artificial methods, directly within the uterus or by laboratory procedures. Presently, the following ART methods are often used:
In-Vitro Fertilization (IVF)
In-vitro fertilization is certainly the best known and the most frequently applied artificial method to induce fertilization. Applying this method, fertilization usually takes place outside of the female body, i.e. "in vitro", as the name tells, which is Latin and means "in the glass".
For this purpose, several oocytes are taken from the female ovaries and put into a special liquid. A selected sperm cell is then added to this liquid, in order to fertilize one of the oocytes. After the fertilized oocyte developed to an embryo, it is re-transferred to the uterus to pursue its natural development to a baby. This technique is mainly applied in women suffering from dysfunctions of their ovaries.
However, fertilization may also be performed within the female body. These methods are called "Gamete Intra-Fallope Transfer - GIFT" or "Zygote Intra-Fallope Transfer - ZIFT", depending upon the procedure applied.
Gamete Intra-Fallope Transfer (GIFT)
Applying this method, via laparoscope the oocytes (taken before from the female ovaries) and the male sperm cells are re-transferred into the fallopian tube where fertilization may take place, followed by the natural development of the foetus.
Zygote Intra-Fallope Transfer (ZIFT)
This method is similar to the GIFT method; however, fertilization of the oocyte is induced outside of the female body, comparable to the IVF method. Upon development of an embryo, this is re-transferred into the fallopian tube. Ensuring fertilization to have taken place, this method also allows for a natural development of the foetus.
Intracytoplasmic Sperm Injection (ICSI)
The ICSI method is often recommended in case of restricted number or mobility of the male sperm cells. Success of fertilization outside of the female body may be increased by injecting the sperm cell directly into the oocyte, using a thin canula. The fertilized oocyte is then re-transferred to the woman's body, applying one of the methods described above.
In case several oocytes have been fertilized by means of one of the above described methods, embryos which are not re-transferred may be preserved by freezing them in liquid nitrogen, in order to be used later. The possibility to perform implantation of an embryo during the natural ovulation process increases the chances for success.
Donor Oocyte Program (DOP)
In women above the age of 30 years, the success of IVF or a similar method decreases. Also women suffering from ovarian dysfunction (unable to produce oocytes) profit from the DOP, using a donor oocyte. After fertilization has been performed, one of the methods described above is applied, in order to transfer the embryo into the female body and allow for further development to a baby.
Too many factors influence the outcome of artificial fertilization, so that there is never a 100% success rate. In order to maximize the chances for success, due to the demanding procedure and also for financial considerations, many couples decide to have several embryos implanted at the same time. However, three or more embryos implanted at the same time considerably increase the risk for multiple gestation, which may induce major financial and social consequences.