Quality Markers in pre-implantation embryos indicating their implantation potential in vitro – experiences from human assisted reproductive technologies

Abstract

The number of infertile couples around the world is approaching 50 million, prompting them to seek in vitro fertilization in an effort to attain parenthood. The initial in vitro fertilization procedures resulted in an unacceptably high frequency of multiple pregnancies with its attendant problems to the mother and new-born and the financial strain on health services. This has led countries to introduce single embryo transfer in their legislations or guidelines. This in turn puts increased pressure on practising embryologists to improve their methods of embryo selection in order to choose a top-quality embryo having the best chance of implantation and pregnancy and of fulfilling couples’ ultimate desire: that of having of a healthy child.

The aim of this thesis is to identify the markers observable in the pre-implantation embryo during in vitro culture that indicate a greater potential for implantation. While the classical method of selection focuses on features such as pronuclear morphology, fragmentation and multinucleation and blastocyst morphology, time lapse imaging takes into account the dynamic nature of embryonic development, allowing for the identification of morphokinetic characteristics in a non-invasive manner, thus maximising the rate of successful pregnancies. The limitations of this thesis lie in the fact that not enough randomized clinical trials have been carried out, preventing the proper assessment and weighting of the markers identified.