Animal experimentation - Enhanced hatching rate of bovine IVM/IVF/IVC blastocysts using a 1.48-mu m diode laser beam

Purpose: Our purpose was to test whether zona pellucida (ZP) drilling using a 1.48-mu m diode laser beam on bovine IVM/IVF/IVC blastocysts is effectiv e for embryo hatching. Methods: Blastocysts produced in vitro at day 7 after IVF were divided into control and laser-drilled groups, respectively. Results: When the rates of in vitro development of bovine embryos were exam ined, the average cleavage rate (greater than or equal to two-cell) was 82. 3% and the blastocyst rate at day 7 after IVF was 32.5%. Using these blasto cysts, when the laser drilling effect was investigated at 48 hr after treat ment, the total hatching rate in the laser-drilled group (98.0%) was signif icantly higher than that in the control group (60.0%) (P < 0.001). Especial ly, the hatched rate of the laser-drilled group (68.0%) was significantly e nhanced compared with that of the control group (30.0%) (P < 0.001). Conclusions: These results demonstrated that laser ZP drilling on bovine IV M/IVF/IVC blastocysts can significantly increase the hatching rate.