In vitro and in vivo viability of human blastocysts collapsed by laser pulse or osmotic shock prior to vitrification
Hiroshi Iwayama, Shinichi Hochi, Masanori Yamashita, Hiroshi Iwayama, Shinichi Hochi, Masanori Yamashita
Abstract
Purpose: This study was designed to investigate whether artificial shrinkage, induced by a laser pulse or hyperosmotic sucrose solutions, improves in vitro survival and/or implantation of vitrified-warmed human expanded blastocysts.
Methods: Before Cryotop vitrification, the blastocoelic cavity was collapsed either by a laser pulse or sucrose solutions. Non-treated blastocysts were used as control. Post-warm blastocyst survival and implantation after transfer were examined. Implantation rate outcome was retrospectively analyzed by morphological grading and developmental kinetics of post-warm blastocysts.
Results: Survival rates in the three groups were high. Implantation rates in the laser-pulse group (59.7%) were comparable with those in the sucrose group (49.3%), and were significantly higher than those in the control group (34.2%). The proportion of blastocysts showing fast development tended to be higher when the blastocysts underwent artificial shrinkage treatment before vitrification. There was no clear correlation between morphology of post-warm blastocysts and implantation rate.
Conclusion: Artificial shrinkage treatment before vitrification is associated with an increased probability of fast-developing embryos, resulting in higher implantation rates.
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Source: PubMed