Purpose: During laboratory manipulations, oocytes and embryos are inevitably exposed to suboptimal conditions that interfere with the normal development of embryos.
Materials and methods: In this study, we examined the effects of antioxidants, feeder cells and a conditioned medium on embryo development and cleavage rate following exposure of the embryos to suboptimal conditions. We exposed mouse two-cell embryos to visible light and divided them into four groups: control (E-ctr), co-culture (Co-c), conditioned medium (Cndm) and antioxidant-plus medium (Aopm). We used human umbilical cord matrix-derived mesenchymal cells for co-culture. A group of embryos was not exposed to visible light and served as the non-exposed control (NE-ctr) group.
Results: The developmental rate was higher in NE-ctr embryos than in the E-ctr group. Exposed embryos in the various groups showed a comparable developmental rate at different stages. Blastomere number significantly increased (P < 0.05) in the Co-c and Aopm groups compared with the E-ctr and Cndm groups. No significant difference was observed between the Co-c and Aopm groups.
Conclusions: Our data indicate that in suboptimal conditions, antioxidants could improve the embryo cleavage rate in the same way as feeder cells. Antioxidants probably improve embryo quality through their ability to scavenge reactive oxygen species.