Effects of partial or complete laser-assisted hatching on the hatching of mouse blastocysts and their cell numbers

Chanchai Chailert,Sudarat Samchimchom,Usanee Sanmee,Waraporn Piromlertamorn,Teraporn Vutyavanich

doi:10.1186/1477-7827-11-21

Chanchai Chailert, Sudarat Samchimchom + Show 3 more

Open Access

https://doi.org/10.1186/1477-7827-11-21

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Abstract

BackgroundIt is still debatable whether a full-thickness assisted hatching (AH) is better than the partial zona thinning. In this research, we used a mouse model to study the effect of partial and complete laser-AH on the rate of completely hatched blastocyst and their cell numbers.MethodsIn experiment 1, mouse morulae had 0, 1, 2 or 3 full-thickness openings of 10 microns created in the zona pellucida with an infrared laser beam. In the second experiment, 0, 1 and 2 openings of 20 microns were studied. In the third experiment, a full-thickness opening of 20 microns or quarter-thinning of the zonal circumference to a depth of 90% was compared with non-AH controls.ResultsNo difference in blastocyst formation was found in laser-treated groups and in the controls. In experiment 1, the rate of completely hatched blastocysts was significantly lower than the controls. In experiment 2 when the size of the opening was increased, blastocysts completely hatched at a significantly higher rate than that in the controls. In experiment 3, the rate of completely hatched blastocysts was the highest in the full-thickness group. Cell numbers in completely hatched blastocysts from both AH groups were significantly fewer than those in the controls.ConclusionsFull-thickness opening resulted in a higher rate of completely hatched blastocysts than quarter zonal-thinning and controls, but the cell numbers were significantly decreased.

Highlights

It is still debatable whether a full-thickness assisted hatching (AH) is better than the partial zona thinning
There was a significant difference in the number of inner cell mass (ICM), TE and total cells, but not in ICM/TE ratio between AH and non-AH blastocysts (Table 2)
There was a significant difference in the number of ICM, TE, and total cells between control and laser-AH blastocysts, but not in ICM/TE ratio (Table 3)

Summary

Introduction

It is still debatable whether a full-thickness assisted hatching (AH) is better than the partial zona thinning. We used a mouse model to study the effect of partial and complete laser-AH on the rate of completely hatched blastocyst and their cell numbers. An infrared laser system appears to be the most suitable method for assisted hatching, as it has good repeatability and consistency between operators and is simple to perform [1,2,3]. It is debatable whether a full-thickness opening is better than the partial zona thinning.

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