Reproductive biomedicine online最新文献

Research question: Can GV-oocytes serve as an effective model to test the efficacy of ultra-fast vitrification (UFV)/ rapid elution (RE) treatments to support reliable, high survival rates and sustained functionality?

Design: Prospective pilot cohort studies were performed to investigate the feasibility of non-equilibration, UFV to sustain cellular integrity and development in contrast to control vitrification (CV: 10-15min ES/ 1min VS). In Phase 1, we applied a 2 × 2 factorial design (n=25-30 eggs/group) to evaluate post-warming dilution treatments: conventional multi-step (CD) versus rapid elution (RE; one-step), including an apriori fresh egg control group. Phase 1/2 focused on survival and maturation assessments, including meiotic spindle formation (Phase 2).

Results: The survival of EG/DMSO treated UFV oocytes in Phase 1 and 2 was not different to spontaneous degeneration seen in the fresh IVM control groups (3.2%) but was higher than CV treated oocytes immediately post-warming (p<0.03). Of the intact GVs, no difference in IVM-MII development was detected (52.6 -58.3%) at +48h IVM across all groups. Meiotic spindle integrity of MII oocytes was normal in all treatment groups.

Conclusions: As originally reported by Gallardo (2019), non-equilibrated dehydrated human oocytes can effectively vitrify after UFV/CD treatment. We further verified the resiliency of oocytes to withstand RE treatment and continue to develop normally, like fresh GV-matured oocytes. Furthermore, we confirmed that the meiotic spindle formation and density of UFV/RE-treated GV oocytes was similar to fresh controls. Overall, the GV-model proved to be a useful resource to substantiate the promising potential of UFV technology to reliably achieve high survival and normal developmental competence in a more time efficient manner.

Research question: Will ultra-fast vitrification (UFV) and rapid elution of mature human oocytes retain the reliable, high survival rates and meiotic spindle normality seen in the germinal vesicle model, and will these oocytes maintain their developmental competence to form blastocyst-stage embryos following artificial oocyte activation (AOA)?

Design: Conventional vitrification treatment was compared with UFV treatment in mature, germinal-vesicle-derived oocytes (Phase 2, Expt. 2, n = 50) and substandard donor oocytes, metaphase I-metaphase II (MII) oocytes and poor-quality MII oocytes (n = 222). Post-warming survival, the integrity of the meiotic spindle and AOA-related development were assessed.

Results: Overall survival rates were higher (P = 0.003) for UFV/rapid elution treatment (94-100%, mean = 98%) compared with conventional vitrification/control dilution treatment (80-90%, mean = 83.3%). MII oocytes derived from immature germinal vesicles following conventional vitrification/control dilution or UFV/rapid elution treatments proved to be capable of activated development (54-71% cleavage rate), with four blastocysts produced. AOA treatment with DMAP exposure yielded optimal activated development. When vitrifying mature oocytes, both UFV and conventional vitrification treatments exhibited normal activated development and blastocyst production (34.9% and 31.7%, respectively).

Conclusions: Considering that oocyte freezing was deemed non-experimental based primarily on healthy live births from frozen-oocyte-derived embryo transfer the validation of normal blastocyst formation using the novel UFV approach is a critical accomplishment. The UFV method for oocyte cryopreservation represents a strategic deviation from traditional semi-equilibration vitrification protocols. UFV is a more time-efficient approach that consistently yields a higher survival rate, and thus has the potential to create more embryos. These findings justify proceeding with strategic clinical trial applications.

With a new Netflix film Joy telling the dramatic story of IVF, Dr Kamal Ahuja recalls the inspirational role that the late Sir Robert Edwards played in his own career and in the foundation of the London Women's Clinic.