AN INNOVATIVE STRATEGY IN SELECTING OOCYTES WITH HIGH IMPLANTATION POTENTIALITY FOR INTRACYTOPLASMIC SPERM INJECTION PROCEDURE

Abstract

The aim of the research was to investigate the apoptosis rate of individual cumulus cell-oocyte complexes (COC), associated to the level of pAKT, to verify the difference between oocytes who produce embryos able to reach the blastocyst stage compared with embryos arrested during the in vitro culture. It was demonstrated that DNA fragmentation in cumulus cells was remarkably lower in patients who achieved a pregnancy after ICSI cycles, related to the quality of oocytes and embryos1,2. AKT pathway plays a critical role in the regulation of cell survival, and most growth factors activate this pathway3. The study focused on 53 patients, involved after informed consent. In this prospective and randomized study, it has been measured the DNA fragmentation rate and the level of pAKT in cumulus cells of individual COC for each follicle containing a mature oocyte. Normo-responder patients have been selected. DNA fragmentation rate in cumulus cells has been examined with the use of a TUNEL assay in situ . pAKT has been examined by immunological assay in situ . Statistic of molecule expression and DNA fragmentation was tested through the repeated measures ANOVA test of log-transformed variables. Out of 255 MII oocytes, 197 were fertilized and the derived embryos had the following evolution: 117 completed the development to blastocyst (day 5or 6) and were transferred in uterus, 57 were vitrified at blastocyst stage and 23 were arrested during in vitro culture at different stage of cleavage. In conclusion we found a statistical difference between the DNA fragmentation rate of cumulus cells between the arrested embryos compared to the transferred and vitrified blastocysts (p=0.004), confirming that apoptotic rate of the cumulus cells could be considered as a marker of oocyte competence. Likewise we a found statistical significance between oocytes resulting in transferred blastocyst and arrested embryos in the ratio pAKT/TUNEL (p=0.043). Therefore, the ratio pAKT/TUNEL could be considered also a marker of oocyte quality. More studies are needed to confirm these data and to determine the how these molecular pathways are involved on the oocyte competence.