Supplementation Strategies to Improve Vitrification-Induced Cryodamage in Oocytes and Embryos: A Narrative Review

Vitrification has revolutionized oocyte and embryo cryopreservation in assisted reproductive technology, enabling the preservation of female fertility. It safeguards the reproductive potential of women facing medical treatments or elective delay of childbearing by preserving unfertilized oocytes, enabling in vitro fertilization, storing supernumerary embryos, and enabling elective single embryo transfers. However, vitrification-thawing procedures are known to compromise oocyte and embryo competence through oxidative stress, mitochondrial dysfunction, and cytoskeletal damage, leading to poor functional and developmental competence of the oocytes and embryos. To counter these detrimental effects, supplemental strategies that can improve the cryotolerance, cryosurvival, or post-thaw functionalities of the oocytes and embryos are of considerable interest in the cryobiology field. This review consolidates findings of 118 studies across human, porcine, ovine, bovine, camel, and murine models evaluating the antioxidants, lipid metabolism modulators, mitochondrial protectants, and other bioactive supplements to mitigate vitrification-induced cryodamage. The review presents the phase-specific supplementation strategy during pre-vitrification, vitrification, and post-warming phases to improve the vitrification-thawing outcomes of oocytes and embryos. By consolidating mechanistic and strategic evidence, this review aims to provide a basis for a supplementation protocol in assisted reproductive technology and cryobiology.