IFFS/JSRM International Meeting 2015(2015.4.26-29 Yokohama）

What is the most important factor of the ICM hatching in frozen-thawed blastocysts cycles?

• Objective

  We investigated the most important factor of the ICM hatching by comparing in 4 parameters, the grade of ICM or TE, the zona drilling size and the area of hatching.

• Materials and Methods

  We dealt with total 207 frozen-thawed blastocyst transfer cycles from January 2010 to July 2014. All blastocysts were cryopreserved by vitrification at day 5 or 6. After thawing, blastocysts were operated assisted hatching by zona drilling method, and cultured for 2~4 hours until the embryo transfer. Each blastocyst was beginning hatching or already hatched and taken a picture just before the embryo transfer to use this study. Retrospectively, we compared the number of the hatched ICM in 4 parameters, the grade of ICM or TE (A or B vs. C), the zona drilling size (40µm< vs. <40µm) and the area of hatching (ICM side vs. Opposite side).

• Results

  The characteristics among 4 parameters weren’t significant differences in the patient’s age, time of cycle, culture date and hours. There were no significant differences in the rate of the hatched ICM by the grade of ICM (13.9% (24/173)) vs. 13.0% (3/23)) and TE (14.7% (17/116) vs. 12.5% (10/80)), and the zona drilling size (14.6% (12/82) vs. 13.4% (9/67)). However, by the area of hatching, the rate of the hatched ICM was significantly higher in ICM side than Opposite side (12.0% (12/82) vs. 0.0 %( 0/62); p<0.01)).

• Conclusions

  We concluded the most important factor of the ICM hatching is the area of hatching and that is affected by the area of the assisted hatching.