Ongoing pregnancy after re-vitrification of cleavage stage embryos

Cryopreservation of gametes and embryos leads to increased cumulative pregnancy rates along with restored costs of artificial reproduction techniques (ART). Vitrification, a novel method, is now being widely used in ART laboratories due to high survival rates along with low cost and simplicity. However the safety and outcome of repeated vitrification procedure has not been clearly determined in human embryos. In this report an ongoing pregnancy after re-vitrification and transfer of cleavage stage embryos was described.