**2. Materials and methods**

*Innovations in Assisted Reproduction Technology*

the "father" of the fist "IVF-Baby."

reproductive medicine.

embryos for primary transfer.

approaches will be discussed.

process will lead to a successful pregnancy.

There are large differences between countries concerning the number of embryos transferred and the resulting multiple births that can occur following the multiple embryo transfer. Multiple pregnancies are classified as high-risk pregnancies and pose a significant health risk to both the mother and baby. However, regardless of that, the practice of multiple embryo transfer is still present, and it is being widely used in order to increase the chances of pregnancy. Currently, efforts are made to reduce the number of multiple embryo transfer, and a mean of 1.81 embryos per transfer is being reported. In Europe, according to the report of the European Society of Human Reproduction and Embryology, the number of multiple delivery rates for embryo transfers dropped from 26.9% in year 2000 to 17.5% in 2014 (latest data available), and it is expected to decline further. Some countries, e.g., Sweden, has reached a very low multiple delivery rate, and the single embryo

The importance of IVF in society is also highlighted by the 2010 Nobel Prize which has been awarded to Robert Edwards who is, together with Robert Steptoe,

The IVF process is an utmost stressful, both physically and psychologically, for both parents but primarily for the mother-in-being. A number of physical examinations and medical procedures are being performed in order to ensure that the

During the IVF process, especially when decisions are made which embryo shall be transferred in order to ensure the greatest chance for success, the best possible decision, based on the fast and accurate information on the status of the embryo, is needed. Due to the increasing age of mothers-to-be, during the past years, a steady increase in pregnancies following artificial reproductive techniques (ART), namely, IVF and intra-cytoplasmatic sperm injection (ICSI), was observed. The reasons for this development must be seen in economic, educational, and social factors, which lead to steadily rising rates of elderly patients. With increasing age, fecundability and fertility decrease. However, the advances made in reproductive medicine itself might be one of the reasons, why an increasing number of women delay childbearing, hoping for late babies and consciously making decisions to use the help of

The elevation of pregnancy rates for IVF procedures is certainly needed in order

to reduce the burden on patients and lower costs affiliated with the procedures, which very often must be repeated until a pregnancy is reached and the embryo develops to successful birth. New technologies and methods more efficient than the current approach using PGS are needed. One new approach could be the analysis of the embryos' proteome during the IVF process. This means to analyze the specific proteins that are secreted by the embryo in the IVF surrounding of the culture medium. Routinely, the medium left after embryo transfer is being discarded. The multiple embryo transfer occurring during the IVF procedure is necessary after the fertilization step, and the spent media are a rich source of biological material that can be used for diagnostic purpose. This procedure of embryo transfer to a new culture medium is essential for the embryo's development and occurs daily or at

least when the embryos have achieved the stage of embryoblast at day 4.

The spent medium can be useful for a detailed examination of proteins and lipids that were secreted by the embryo during each stage of development and can be used for the estimation of the "embryo quality" and selection of corresponding

An overview of technologies and approaches being used and a simplified experimental approach are presented in this chapter. The method used in our laboratory is used just as an example of the technologies used, and a number of different

transfer was performed in more than two-thirds of all transfers.

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