Reliable preimplantation genetic diagnosis in thawed human embryos vitrified at cleavage stages without biopsy

Purpose To evaluate preimplantation genetic diagnosis (PGD) efficiency in thawed human embryos vitrified without biopsy. Methods In this retrospective clinical study, 21 PGD cycles were carried out using fresh and vitrified-thawed embryos collected from 21 patients. Results One hundred and ninety-nine embryos from patients with aneuploidy, single gene defects, or chromosomal translocations were vitrified at the cleavage stages; 93.5% of the embryos survived the vitrification procedure. Conclusive FISH results were obtained in 98.4% of the fresh and 99% of the frozen-thawed embryos screened for aneuploidy or chromosomal translocations. Conclusive PCR test results were obtained in 100% of the fresh and 93.9% of the frozen-thawed embryos screened for single gene defects. The overall clinical pregnancy rate per cycle was 57.1%. To date, 13 healthy children have been born. Conclusion Reliable genetic diagnosis can be performed in thawed human embryos vitrified without biopsy. However, further research is required to support this conclusion.