Cell-free DNA in Embryo Culture Media as Non-invasive Biomarker of the Quality of Embryo Cleavage

Abstract

Background: The success of in vitro-fertilization (IVF) cycles is determined in large part by the quality of embryo cleavage, which in turn, is dependent on the quality of the embryo culture media (CM). Many factors can influence the quality of embryo CM, one of which is the levels of Cell Free Deoxyribonucleic acid (DNA). Understanding the association between Cell-free DNA levels in embryo CM and the quality of embryo cleavage could help improve the quality of IVF techniques. Methods: This prospective study was conducted with 96 spent CM from patients undergoing IVF cycle, in order to determine relationships of Cell-free DNA levels in embryo CM with embryo cleavage quality on day 3. After intracytoplasmic sperm injection (ICSI), 48 embryos were evaluated on day 3 of their development, according to their cell number. Day 2 and day 3 CM corresponding to each one of the embryos was analyzed, by quantitative PCR, for estimation of Cell-free DNA levels. Results: The results revealed a significant increase in Cell-free DNA levels on day 2 CM corresponding to 4 to 6 cell embryos compared to those corresponding to 7 to 8 cell embryos (p=0.04).  As for day 3 CM, the results showed no significant difference between the Cell-Free DNA levels in CM of 7-8 and those of 4-6 cell embryos (p=0.4). Also, cell free DNA levels in embryo CM, were significantly higher on day 2 compared to day 3 for both 7-8 and 4-6 cell embryos (p=0.03; p=0.04).   Conclusion: We conclude that cell-free DNA levels in CM might be associated with delayed embryo cleavage.