The overall aim was to evaluate a non-invasive technique for the assessment of oocytes and embryos using polarized light microscopy (PolScope-LC) with the goal of improving success rates in IVF. A literature review revealed little validation of the PolScope techniques in published work. A reproducible and accurate method for measuring the zona pellucida (ZP) thickness and density involving the PolScope computer software was validated by achieving low coefficient of variance and small inter/intra observer errors. Utilizing this method, 1477 oocytes from 211 stimulated cycles were analysed in this thesis. Results showed that increasing age has an adverse effect on the ZP thickness and density. Study of extended culturing of embryos showed that the ZP starts thinning as early as day 3 and embryos tend to have denser zonas over time. Standardisation of timing of PolScope observations in relation to the meiotic spindle was studied. Metaphase II oocytes were examined sequentially in culture from aspiration until microinjection using the PolScope The spindle is a highly dynamic structure that can appear and disappear over time in culture. A visible spindle was detected in 58% of the oocytes immediately after aspiration. This percentage increased until it stabilised at 39-40hrs post hCG and then declined significantly. Average spindle signal intensity increased over time reaching its peak at 39-40hrs post hCG, then declined significantly by 40.5hrs post hCG. The importance of spindle presence and morphology was investigated by following up embryos created after sperm injection at 39-40hrs post hCG. There was a significant relationship between normal meiotic spindle shape and density and embryo quality. A higher percentage of ???usable??? embryos, and all of pregnancies, arose from oocytes with a normal barrel shaped spindle. Finally, the impact of two issues related to spindle formation - the type of hCG used to trigger oocyte maturation and the site of microinjection during ICSI were assessed using the PolScope. The results showed a biological difference in spindle formation and embryo quality between rhCG and uhCG. In a separate randomised trial embryo quality was better when injecting the sperm in the vegetal pole away from the spindle during ICSI. The results from this thesis suggest that PolScope, if appropriately applied, may assist in improving IVF outcome.
| Identifer | oai:union.ndltd.org:ADTP/243009 |
| Date | January 2007 |
| Creators | Kilani, Suha, School of Medicine, UNSW |
| Publisher | Awarded by:University of New South Wales. School of Medicine |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Suha Kilani, http://unsworks.unsw.edu.au/copyright |
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