STUDY OF CELL FREE MITOCHONDRIAL DNA CONTENT OF EMBRYO CULTURE MEDIUM AT DAY 3 AND BLASTOCYST DEVELOPMENT AND QUALITY DURING INTRACYTOPLASMIC SPERM INJECTION CYCLES.

Background: The morphological criteria are still the main method during In Vitro Fertilization (IVF) technology for selection of human embryos with possible high implantation rates and successful pregnancy potential. Embryo fragmentation is routinely used as the main tool for grading the human embryo and its implantation potential. Fragments of human embryo cells are the sources of cell free mitochondrial DNA (mtDNA) that released into the embryo culture media (secretome). Cell free mtDNA detection in human embryo secretome can be used as a non invasive objective tool to appraise the fragmentation of the embryo cells and thus the growing potential to the blastocyst stage. Aim: the aim of the present research paper was to evaluate the correlation between cell free Mitochondrial DNA content of embryo culture medium at Day 3 and blastocyst growth and grading during Intracytoplasmic Sperm Injection (ICSI) cycles. Subjects and Methods: 50 spent embryo culture media were collected from 17 ICSI cycles. In twenty good quality grade 1 embryos; culture samples were collected and embryos allowed continuing in culture to reach blastocyst stage. After extraction and purification; mitochondrial DNA was profiled by specific semi quantitative method (Agarose gel electrophoresis). Each Day 3 embryo was morphologically graded according to the current consensus system (Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology, 2011. At D5 blastocysts were morphologically scored according to criteria described by Gardner and Schoolcraft (1999) and recently agreed by an expert panel of scientists (Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology, 2011). Results: Insignificant correlation was found between mtDNA profiling in D3culture media of embryonic development and embryo fragmentation, but when correlating mtDNA profile on D3 and embryo fragmentation and grade; highly significant correlation was found with embryos of G2 or lower quality. Significant correlation was detected between free mtDNA amount and blastocyst formation. Also, a highly significant correlation was noticed between mtDNA profiling on D3 for those embryos and their blastocyst grading in D5. Conclusion: -Results of the current study are suggestive of a significant correlation between the human embryo culture media mtDNA profile in D3 and the degree of embryo blastomeres fragmentation especially in bad quality embryos; with significant correlation between mtDNA profiling and blastocyst formation and quality in Day5.