A monocentric analysis of the efficacy of extracellular cryoprotectants in unfrozen solutions for cleavage stage embryos.

BACKGROUND: In the absence of international guidelines indicating the usage of vitrification rather than slow-freezing, the study aim was to analyze a large cohort of slow-frozen/thawed embryos to produce a rationale supporting the standardization of IVF cryopreservation policy. METHODS: This retrospective analysis included 4779 cleavage stage embryos cryopreserved by slow-freezing/thawing from September 2009 to April 2017 at a single Center. Biological and clinical outcomes of three different commercial kits adopted sequentially, i.e. Vitrolife Cleave Kit® from Vitrolife (kit 1) vs. K-SICS-5000 Kit® and K-SITS-5000 Kit® from Cook Medical (kit 2) and Freeze/Thaw 1™ Kit® from Vitrolife (kit 3) were collected and compared in the light of cryoprotectants composition. RESULTS: Kit 3 compared to kit 1 and kit 2 showed significantly (P < 0.001) higher embryo survival (79.9% vs. 75.6 and 68.1%, respectively) and frozen embryo replacement (91.5% vs. 86.5 and 83.3%, respectively) rates, and significantly (P < 0.001) lower blastomere degeneration rate (41.5% vs. 43.6 and 52.4%, respectively). No significant difference for clinical outcomes was observed among kits. Only a slight positive trend was observed for kit 3 vs. kit 1 and kit 2 on delivery rate per thawing cycle (7.12% vs. 4.19 and 4.51%, respectively; P < 0.058) and live birth rate (3.07% vs. 2.59 and 1.93%, respectively, P < 0.069). Thawing solutions of kit 3 were similar to those of any warming protocol. CONCLUSIONS: A defined concentration of extracellular cryoprotectants in thawing/warming solutions had a beneficial effect on the embryo cryosurvival rate. Results could provide the rationale for the adoption of a single standardized warming protocol.

The effect of the 2004 Italian legislation on perinatal outcomes following assisted reproduction technology.

OBJECTIVE: To assess the perinatal outcomes of the first three years under the 2004 Italian reproductive legislation obligating transfer of all embryos resulting from insemination of < or =3 oocytes. STUDY DESIGN: We compared the perinatal results of clinical assisted reproductive technology (ART) pregnancies during the three years following the new Italian legislation with the previous three years. RESULTS: There were 583 and 571 clinical pregnancies during the respective periods. Before the law, the overall embryonic and fetal loss rates were significantly higher resulting in a significantly lower rate of live born infants and significantly fewer clinical pregnancies with at least one live born infant. Quadruplet and quintuplet pregnancies were entirely eliminated following the 2004 law but the neonatal mortality rate was not different between the two study periods. CONCLUSION: The 2004 Italian infertility legislation led to improved quantitative and qualitative outcomes of ART.