Preliminary Investigation on the Role of Vitrification in Pre-Implantation Genetic Diagnosis

ObjectiveTo investigate the feasibility of vitrification of blastocysts following blastomere biopsy.MethodsAmong patients undergoing pre-implantation genetic diagnosis (PGD), artificial shrinkage of the blastocoelic cavity and subsequent vitrification of applicable surplus blastocysts after day-3 blastomere biopsy were performed. According to patient requirements, thawed blastocysts were transferred into patients due to pregnancy failure after fresh embryo transfer, ectopic pregnancy, ovarian hyperstimulation.ResultsTwenty-four PGD cycles were carried out. According to genetic diagnosis and the development of blastocysts, transfer was cancelled in 7 cycles due to absence of applicable embryos or ovarian hyperstimulation. In the remaining 17 cycles, 26 blastocysts were thawed and transferred, which resulted in 13 implanted (50.0%). Clinical pregnancies were observed in 11 patients (64.71%). Following transfer, 30 applicable blastocysts in 10 cycles were cryopreserved. Six patients received transfer of thawed blastocysts. All 8 thawed embryos survived and were transferred, and singleton pregnancies occurred in 5 patients. Two women delivered healthy infants and 3 pregnancies are ongoing.ConclusionVitrification with artificial shrinkage is effective for preserving blastocysts following blastomere biopsy.