Aila Coello1, Marcos Meseguer2, Arancha Galán1, Lucia Alegre1, José Remohí1, Ana Cobo1. 1. Instituto Valenciano de Infertilidad, INCLIVA-Universidad de Valencia, Valencia, Spain. 2. Instituto Valenciano de Infertilidad, INCLIVA-Universidad de Valencia, Valencia, Spain. Electronic address: marcos.meseguer@ivi.es.
Abstract
OBJECTIVE: To describe the morphological dynamics of vitrified/warmed blastocysts and to identify quantitative morphological variables related to implantation. Subsequently, by using the most predictive parameters, to develop a hierarchical model by subdividing vitrified/warmed blastocysts into categories with different implantation potentials. DESIGN: Observational, retrospective, cohort study. SETTING: University-affiliated private IVF center. PATIENT(S): The study included 429 vitrified/warmed blastocysts with known implantation data, which were evaluated by time-lapse imaging. Blastocysts were routinely placed in EmbryoScope (Vitrolife) immediately after warming until transfer. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Embryos were vitrified and warmed by the Cryotop method (KitazatoBiopharma). The studied variables included the initial and minimum thicknesses of zona pellucida (μm), the initial and maximum areas (μm2), the area of inner cell mass (μm2), expansion (whether the embryo reexpands or not after warming), and collapsing or contraction after warming. After defining the optimal ranges according to the consecutive quartiles with the highest probability of implantation, a logistic regression analysis was performed by combining the former variables and the blastocyst morphological classification criteria defined by the Spanish Association of Embryologists into A, B, C, or D categories. RESULT(S): Reexpansion of vitrified/warmed blastocysts correlated strongly with implantation (44.6% for reexpanded vs. 6.5% for the blastocysts that did not reexpand after warming). Throughout the logistic regression analysis, the model identified the maximum blastocyst area, odds ratio (OR) = 0.41 (95% confidence interval [CI], 0.22-0.77), followed by the initial area, OR = 0.62 (95% CI, 0.35-1.08) as the most predictive variables related to implanting embryos. Blastocyst morphology was not considered relevant in our model. The hierarchical tree model subdivided embryos into four categories, A-D, with lowering expected implantation potentials (from 47.3% for A to 14.2% for D). CONCLUSION(S): The analysis of warmed blastocysts by time-lapse imaging may provide objective quantitative markers for the blastocyst implantation potential. We propose a hierarchical model to classify vitrified/warmed blastocysts according to their implantation probability. The observed correlations and the proposed algorithm should be validated in a prospective trial to evaluate its efficacy.
OBJECTIVE: To describe the morphological dynamics of vitrified/warmed blastocysts and to identify quantitative morphological variables related to implantation. Subsequently, by using the most predictive parameters, to develop a hierarchical model by subdividing vitrified/warmed blastocysts into categories with different implantation potentials. DESIGN: Observational, retrospective, cohort study. SETTING: University-affiliated private IVF center. PATIENT(S): The study included 429 vitrified/warmed blastocysts with known implantation data, which were evaluated by time-lapse imaging. Blastocysts were routinely placed in EmbryoScope (Vitrolife) immediately after warming until transfer. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Embryos were vitrified and warmed by the Cryotop method (KitazatoBiopharma). The studied variables included the initial and minimum thicknesses of zona pellucida (μm), the initial and maximum areas (μm2), the area of inner cell mass (μm2), expansion (whether the embryo reexpands or not after warming), and collapsing or contraction after warming. After defining the optimal ranges according to the consecutive quartiles with the highest probability of implantation, a logistic regression analysis was performed by combining the former variables and the blastocyst morphological classification criteria defined by the Spanish Association of Embryologists into A, B, C, or D categories. RESULT(S): Reexpansion of vitrified/warmed blastocysts correlated strongly with implantation (44.6% for reexpanded vs. 6.5% for the blastocysts that did not reexpand after warming). Throughout the logistic regression analysis, the model identified the maximum blastocyst area, odds ratio (OR) = 0.41 (95% confidence interval [CI], 0.22-0.77), followed by the initial area, OR = 0.62 (95% CI, 0.35-1.08) as the most predictive variables related to implanting embryos. Blastocyst morphology was not considered relevant in our model. The hierarchical tree model subdivided embryos into four categories, A-D, with lowering expected implantation potentials (from 47.3% for A to 14.2% for D). CONCLUSION(S): The analysis of warmed blastocysts by time-lapse imaging may provide objective quantitative markers for the blastocyst implantation potential. We propose a hierarchical model to classify vitrified/warmed blastocysts according to their implantation probability. The observed correlations and the proposed algorithm should be validated in a prospective trial to evaluate its efficacy.
Authors: Ji Young Hwang; Jae Kyun Park; Tae Hyung Kim; Jin Hee Eum; HaengSeok Song; Jin Young Kim; Han Moie Park; Chan Woo Park; Woo Sik Lee; Sang Woo Lyu Journal: Clin Exp Reprod Med Date: 2020-11-10
Authors: Susanna Apter; Thomas Ebner; Thomas Freour; Yves Guns; Borut Kovacic; Nathalie Le Clef; Monica Marques; Marcos Meseguer; Debbie Montjean; Ioannis Sfontouris; Roger Sturmey; Giovanni Coticchio Journal: Hum Reprod Open Date: 2020-03-19