The role of PGS in Repeated Implantation Failure

Preimplantation genetic screening ( PGS ) has been increasingly used in many infertility centers in the past years providing that using this technique may lead to a more success rate. Since the introduction of the IVf technique in 1978, millions of births have been reported using this technique. Although this method has been used to provide pregnancy for many couples, on average only 35% to 40% of the couples get pregnant after completion of one IVF cycle . Therefore, IVF failure is one of the main challanges in infertility treatment. So far, many studies have been conducted to evaluate the causes and treatment of IVF failure. Basically the main causes of treatment failure are divided into two categories of embryonal and uterine factors. Many studies have shown that the greatest cause of repeated IVF failure is related to the embryonal aneuploidy . Since 1995 genetic diagnostic techniques before implantation have been introduced as one of the promising therapies in this field. The ineffectiveness of the PGS method with the FISH technique, which was limited to a review of only 5 to 7 chromosomes on 3-day embryos was the reason for replacing it with the newer PGS / NGS technique on 5 -day embryos , which was feasible with a more accuracy and evaluation of all 23 pairs of chromosomes. Although the use of this method has led to increased success in the treatment of IVF and is used in many treatment centers, some of the world s leading researchers believe that the use of this technique should be limited and selective and not routinely recommended in all.