Co-culture Versus Sequential Culture System in Advanced Maternal Age.

Fertilization and embryo development in vivo occurs in appropriate conditions in the mammalian reproductive tract. However in assisted reproductive technology (ART) embryos and oocytes are exposed to certain factors such as temperature, O2 pressure and pH fluctuations that may affect embryo development and viability in vitro. In Preimplantation Genetic Screening program (PGS) the investigators need to culture the embryos until day 5 so the requirement of culture techniques must be optimal to produce acceptable blastocyst rates. As it has been shown before, embryo culture conditions have the potential to impact biopsied embryos and hence PGS success rates.

Nowadays the coculture system with endometrial cells could be an alternative option to improve the blastocyst rates since some publications have indicated that endometrial cells may provide trace elements and growth factors that are not present in defined culture media and reproduce physiologic conditions. Although the role of coculture in vitro fertilization (IVF) has been controversial, a recent meta-analysis has established the potential benefits of coculture system.

The aim of this study was to compare embryologic and clinical outcomes in terms of blastocyst, implantation and pregnancy rates to evaluate endometrial epithelial cell (EEC) coculture versus sequential culture system in advanced maternal age ( ≥39 years) in the PGS program.