AbstractTime-lapse system(s) (TLS) have, potentially, two benefits over standard incubation systems; an undisturbed culture environment and an enormous volume of images of the embryos within them. The current research aimed to determine if a TLS could provide a comparably stable culture environment
compared to a standard incubator measured as pH, osmolality and treatment success rates. Second, the hypothesis that patient, treatment and environment specific embryo selection algorithms (ESAs) are required to improve the efficacy of a TLS as an embryo assessment tool was tested.
A TLS was shown to provide a comparably stable environment when compared to a standard incubator in terms of pH and osmolality. In addition, using a strict matched-pair design, embryos cultured in a TLS resulted in a significantly higher implantation, clinical pregnancy and live birth rates. It was
also concluded that, of six published ESAs, none performed with clinically relevant predictive capabilities when applied to the same cohort of known implantation embryos. Owing to this, the identification of five abnormal division events as significantly reducing an embryos implantation potential was performed providing an easily adopted, clinically relevant means to
deselect embryos cultured in a TLS. A regression analysis found a number of treatment and patient parameters having a significant effect on crucial morphokinetic parameters, although no systemic effect was observed. Finally, an interim analysis of a sibling oocyte study of three, commercially available
culture media revealed significant differences in the time of embryo compaction as well as embryo quality and utilisation.
Together, these results highlight that a TLS provides a stable culture environment and leads to increased implantation, clinical pregnancy and live birth rates. It is also likely that the patient, treatment type and environment can significantly alter an embryos morphokinetic profile and specific ESAs are required to unlock the true potential of time-lapse technology.
|Date of Award||28 Jun 2017|
|Supervisor||JEREMY BROWN (Director of Studies)|