Artificial shrinkage of blastocoel using a laser pulse prior to vitrification improves clinical outcome

Abstract

Purpose: Blastocysts contain a large amount of fluid in the blastocoel, which may pose a risk for ice crystal formation during vitrification. This study aimed to evaluate the effectiveness of laser-induced artificial shrinkage of blastocoel before vitrification on clinical outcome. Methods: Patients were divided into two groups: a control group with untreated, expanded blastocysts (n = 115) and a study group with blastocoel artificially eliminated by a laser pulse prior to vitrification (n = 309). Blastocyst survival, clinical pregnancy, and implantation rates were compared. Result(s): The survival rate was significantly higher in the study group compared with the control group (97.3 and 74.9 %, respectively; p > 0.01). The clinical pregnancy and implantation rates of the study group were significantly higher (p < 0.01) than that of the control group (clinical pregnancy, 67.2 vs. 41.1 %; implantation, 39.1 vs. 24.5 %. Conclusion(s): This study demonstrated that the removal of blastocoel fluid before vitrification by laser pulse of in vitro-produced human blastocysts significantly improves blastocyst survival, clinical pregnancy, and implantation rates.