Implantation and pregnancy rates from vitrified embryos

Abstract

The main objective of this study was to evaluate the effectiveness of vitrification technique through embryo viability, embryo implantation rate and clinical pregnancy in patients undergoing controlled ovarian stimulation. Viable embryos of patients deriving from in vitro fertilization were vitrified using the protocol of Irvine Scientific by closed system. 28 cycles of freezing and thawing of embryos were evaluated during the periods from January 2010 to December 2012 in the Clinical Reproduction, Presidente Prudente - SP. Total of 176 embryos was frozen. The average number of frozen/thawed embryos per patient was 5, totaling 140 thawed embryos. These thawed embryos, 78,6% (110/140) displayed viable morphologically (at least 50% from intact blastomeres) and 75% (105/140) of thawed embryos were transferred. In 28 cycles in which there was transference, an average of 3.75 embryos were transferred per patient, from which resulted in 17 biochemical pregnancies and of these 8 pregnancies reached term (28,6%) and embryonic implantation rate was 20%. It can be concluded that the method of embryos vitrification is an effective technique, with high survival rate, allowing the storage of surplus embryos with satisfactory pregnancy rates in thawing cycles.