Comparison of Laser-assisted Hatching and Acidified Tyrode's Hatching by Evaluation of Blastocyst Development Rates in Sibling Embryos: a Prospective Randomized Trial

Objective: To assess two zona drilling methods in terms of blastocyst development rates using sister embryos.

Design: Prospective, randomized study. Sister embryos of 14 patients were randomly assigned on day 3 to acidified Tyrode's zona drilling or to laser zona drilling. After biopsy, subsequent embryo culture until the blastocyst stage (day 5) was performed.

Setting: Private fertility center.

Patient(s): Patients undergoing IVF-preimplantation genetic diagnosis.

Intervention(s): Embryo biopsy using either laser-assisted hatching or acidified Tyrode's hatching on sibling embryos and subsequent blastocyst development evaluation.

Main Outcome Measure(s): Evaluation of blastocyst development in terms of degree of expansion and cell number in the inner cell mass and trophectoderm.

Result(s): Blastocyst development rates (and blastocyst quality) were similarly high in both the acidified Tyrode's hatching group and the laser-assisted hatching group.

Conclusion(s): Laser hatching does not impair embryonic development to the blastocyst stage, demonstrating that laser-assisted hatching is a suitable alternative to the use of acidified Tyrode's solution for zona drilling.