Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Biotechnology

Pre-implantation genetic screening (PGS) aims to help couples lower the risks of transmitting genetic defects to their offspring, this technology has been employed as an embryo selection tool for patients undergoing in vitro fertilization, screening as many chromosomes as possible, in the hope that selecting chromosomally normal embryos will lead to higher implantation and decreased miscarriage rates. Material is collected from the oocyte (polar body), day three old embryo, or increasingly often, from the trophectoderm of a blastocyst. Selection of the diagnostic method depends on the testing center, but methods such as aCGH (Comparative Genomic Hybridization Array) and NGS (Next-Generation Sequencing) are supposed to have the highest reliability and precision.This paper presents a review of the most common abnormalities in human embryos.This study was conducted on 100 infertile women undergoing ICSI cycles with poor prognosis; poor responder women whose age is 27 or more, required 375 I.U. of gonadotropin or more per day to well stimulate their follicles and with history of previous failed ICSI. PGS was performed for 611 embryos for 24 chromosomes. The result showing a significant negative correlation between age and the Euploid embryo with P-value < 0.05. When the age increase there is a notable decrease in the euploid embryo.The highest common abnormalities were occurred in chromosomes number 13, 18, 19 and 22. In conclusion, our results suggest that Preimplantation genetic screening enhances molecular anomalies such as chromosomal abnormalities in patients with poor prognosis and should be offered to them as a routine

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