Modified laser-assisted zonal opening method for human embryo biopsy in preimplantation genetic diagnosis: Preliminary experience

OBJECTIVE: To test the safety and efficacy of a modified laser-assisted zonal opening method for human embryo biopsy. STUDY DESIGN: The embryo was treated with a modified method to create an ample perivitelline space between the zona pellucida and underlying blastomeres. This was done to protect the blastomeres from damage by laser treatment of the zona pellucida. Subsequently, the zona pellucida was completely perforated using a diode laser, and the targeted blastomere was aspirated. In vitro embryo development of the 40 biopsied embryos was compared with that of 322 corresponding control embryos without embryo biopsy. RESULTS: Forty targeted blastomeres were successfully extracted from 40 human embryos. The incidence of embryo development to the blastocyst stage was not different between the biopsied and nonbiopsied groups (55% vs. 54.3%). Furthermore, the percentage of top-scoring blastocysts from biopsied embryos was also similar to that of control embryos (77.3% vs. 78.9%). CONCLUSION: These preliminary results demonstrate that the modified technique for human embryo biopsy in preimplantation genetic diagnosis is simple and safe.