Sex Determination of Preimplantation Embryos Through Non Invasive Technique on Spent Embryo Culture Media

Background: Preimplantation genetic diagnosis/screening (PGD/PGS) was introduced as an alternative method to prevent the birth of children suffering from x-liked genetic disorders. The gender of the embryo before implantation is important in some research, furthermore is used for family balancing. PGD/PGS is an aggressive technique. SRY gene expression begins in male embryos following genome activation in preimplantation embryos. The aim of this study was noninvasive Sex determination of preimplantation embryos based on the presence of SRY RNA in the spent culture medium as a biomarker in sexing of human preimplantation embryos Methods: In this double-blind study, two groups were evaluated. In the first group, the culture medium of human embryos of ART candidates were received, following RNA extraction, the total RNA was immediately reverse transcribed to cDNA. Then PCR was performed for SRY and GAPDH genes. In the second group, PCR was performed directly on the culture medium. The SRY positive embryos were considered as male embryos and those GAPDH positive and SRY negative were considered as females. Results: For the first group, 14 samples were evaluated. We correctly diagnosed all 14 samples. In the second group, we were able to correctly diagnose 10 of the 12 samples. Conclusion: Preimplantation sexing without embryo biopsy on the spent embryo culture media seems to be a reliable tool for non-invasive preimplantation sexing. However, direct PCRbased diagnosis might be lead to false results; this is probably due to DNA contamination of the serum in the culture media.

Keywords:

Preimplantation Genetic Diagnosis , SRY Gene , Embryo , Culture Medium