الفهرس 
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Abstract
Assisted reproduction is now an established method for the treatment of infertility in a multitude of clinical conditions. IVF was first reported by Steptoe and Edwards in 1978. Subsequently ICSI was introduced by Palermo et al in 1992. Today more than 5 million babies have been born as a result of assisted reproduction.
In order to maximize the success rates, infertility specialists are always faced with the dilemma of transferring too many embryos and risking the occurrence of multiple pregnancies with the resulting complications, or transferring too few embryos and risking failure of the procedure. There is, therefore, an urgent need for a simple and practical method for embryo selection in order to maximize the chances of success and minimize the problems of multiple pregnancies in couples treated with assisted reproduction.
Various methods for embryo selection have been suggested and practiced. These include invasive and non-invasive methods. Invasive methods are used to screen the embryos for genetic abnormalities (PGS). They require the performance of an embryo biopsy: a blastomere biopsy at the 8-cell stage or a trophectoderm biopsy at the blastocyst stage. The procedures are expensive and require advanced skills. More importantly, they are not full proof due to the possibility of embryo injury, undetected mosaicism and segmental aneuploidy. This means that some normal embryos may be discarded and some abnormal embryos may be falsely diagnosed as normal. In addition, a meta-analysis of randomized studies conducted in 2011 showed that PGS did not improve the live birth rate compared to morphological selection, although a more recent meta-analysis showed that, in good prognosis patients, comprehensive chromosome screening after blastocyst biopsy was associated with higher clinical implantation and ongoing pregnancy rates (but not higher live birth rates) when the same number of embryos is transferred. Consequently, more infertility specialists are now considering and using non-invasive methods for embryo selection.
Non-invasive methods for embryo selection include (1) selection on the basis of the morphology of individual embryos at the time of transfer, (2) selection on the basis of the morpho-kinetic changes of individual embryos during early developmental stages observed by time-lapse photography, (3) selection on the basis of the oxygen consumption by individual embryos, (4) selection on the basis of various biochemical markers measured in the culture medium of individual embryos, (5) selection on the basis of oxidative stress to which individual embryos are subjected, or (6) combination of some of the above. The aim of this work was to evaluate two of these methods of embryo selection as predictors of clinical pregnancy taking embryo morphology as the reference method.
The aim of this study was to evaluate 3 methods of embryo selection in predicting the embryos with the best method of achieving pregnancy in single embryo transfer cycles. A total of 66 embryos in 66 ICSI cycles were studied: 33 pregnant and 33 non-pregnant cycles.
Each embryo was scored using the Veeck’s scoring method and the spent culture medium of each embryo was analyzed for its content of glucose and
β-hCG using previously validated methods.
The results showed that the Veeck’s embryo score, the measurement of glucose levels and the measurement of β-hCG levels in the spent culture medium are all reliable and practical methods to be used for this purpose. The Veeck’s embryo score had the best predictability followed by β-hCG levels, followed by glucose levels in the culture medium.
In an attempt to improve the predictability of the studied methods, the best predictability was found by combining the 3 methods. This combination was superior to each methods studied alone as well as any combination of 2 methods.
These results should be confirmed in a prospective randomized study in single embryo transfer cycles.