Some fertility centers promote preimplantation genetic screening as a way of improving IVF success rates in women over 35 (defining advanced maternal age).
Now a study in the January 2010 edition of Fertility & Sterility shows that PGS does not significantly improve implantation, pregnancy or live birth rates. In this randomized control study from Belgium, the clinical implantation rate per embryo transferred was compared between the PGS group (analysis of chromosomes 13, 16, 18, 21, 22, X, and Y by FISH) and the control group without PGS.
No differences were observed between the PGS group and the control group for the clinical implantation rate, the ongoing pregnancy rate at 12 weeks and the live born rate per embryo transferred. A normal chromosome component was observed in only 30.3% of the embryos screened by PGS.
In this randomized controlled trial, the results did not confirm the hypothesis that PGS by FISH in 3-Day embryos results in improved reproductive outcome in patients with "advanced maternal age.".
In the future newer techniques of chromosome analysis such as comparative genomic hybridization (CGH) which can analyze all chromosome pairs and the ability to analyze blastocyst cells, freeze the embryos and transfer only chromosomally normal embryos may result in better outcomes and the need to transfer fewer embryos and reduce high-order multiple pregnancies as well.