A new assisted hatching technique using a piezo-micromanipulator

OBJECTIVE: To estimate the efficacy of a new assisted hatching technique using a piezo-micromanipulator to support embryonic implantation. DESIGN: Sibling spare embryos from human cycles of IVF were allocated to either a treated group for assisted hatching by a piezo-micromanipulator or a nontreated control group. SETTING: The Infertility and IVF unit of the Kyoto University Hospital. PATIENT(S): Sixty-eight women undergoing conventional IVF treatment. INTERVENTION(S): One hundred ten spare 4- or 8-cell embryos from 68 patients undergoing IVF were treated with the new assisted hatching technique, and the results were compared with those obtained for 112 sibling embryos without the treatment. In the assisted hatching procedure, zona thinning combined with drilling was performed by the vibration of a microneedle produced by the piezo-micromanipulator unit. MAIN OUTCOME MEASURE(S): The rates of partial hatching and completely hatched blastocysts. RESULT(S): The rates of hatching and of hatched blastocysts per total developing blastocysts were significantly higher in the treated group (86.7% and 33.3%, respectively) than in the control group (15.3% and 2.8%, respectively). CONCLUSION(S): These results demonstrate that the newly devised zona thinning and drilling technique using a piezo-micromanipulator is useful for assisted hatching.