[Pregnancy rate in cryopreserved embryos based on the classical morphologic scoring and the integrity of blastomeres at thawing]. / Tasa de embarazo en embriones criopreservados según la calificación morfológica clásica y la integridad de las blastómeras a la descongelación.

Two different thaw embryo classifications were evaluated, the morphologic classic evaluation (Veeck, 1990) and all blastomeres intact at the time of embryo transfer. We also discuss the clinic parameters and the physiopathological causes implicated in the successful of this treatment. 176 ovarian stimulation cycles and 513 cryopreserved embryos were reviewed. We found better pregnancy rate and delivery rate in embryo transfers were at least one embryo had all blastomeres intact compare with the transfers with good quality embryos (1+, 2+) of the morphologic classic evaluation without statistic significance (p > 0.05). Pregnancy and delivery rate were higher in cases with embryo in pronuclear stage compare with cleavage stage (p < 0.05). The blastomeric harm disturbs the embryo implantation phase and the future is oriented to the microsurgical remove of the damaged blastomeres and the use of assisted hatching.