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Time-lapse analysis and morphokinetic evaluation of fresh vs. vitrified/warmed oocytes, including donor and explorative sibling oocyte cycles

dc.contributor.advisorWindt De Beer, Marie-Lenaen_ZA
dc.contributor.advisorVan Waart, Johannesen_ZA
dc.contributor.advisorEls-Smit, Lydiaen_ZA
dc.contributor.authorRamsay, Dylanen_ZA
dc.contributor.otherStellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Obstetrics and Gynaecology.en_ZA
dc.date.accessioned2020-02-26T05:43:09Z
dc.date.accessioned2020-04-28T12:05:43Z
dc.date.available2020-02-26T05:43:09Z
dc.date.available2020-04-28T12:05:43Z
dc.date.issued2020-03
dc.identifier.urihttp://hdl.handle.net/10019.1/107841
dc.descriptionThesis (MSc)--Stellenbosch University, 2020.en_ZA
dc.description.abstractENGLISH ABSTRACT: BACKGROUND: Infertility is defined as a disorder of the reproductive system whereby there is failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse. The primary objective of Assisted Reproductive Technologies (ART) is to implement fertilization in instances where corrective therapy for male or female patients cannot yield fertilization. During the past three decades infertility has become more prevalent. In addition to this, the commercialized world has experienced a trend of women conceiving their firstborn within their later reproductive years. This trend of delaying motherhood has thus led to the common use of oocyte vitrification protocols, which have become increasingly robust over the years. The validation of the oocyte vitrification protocol essentially came from the comparison of fresh versus vitrified/warmed oocytes and how they succeeded in in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcomes. It was reported that there were no differences in fertilization rates, implantation rate and pregnancy rates when comparing fresh vs. vitrified/warmed oocytes. Furthermore, there is a trend towards implementing morphokinetic analyses to examine the comparisons between fresh and vitrified/frozen oocytes. With the rapid progression in technology within the ART field of medicine, time lapse systems (TLS) presents an extremely unique and promising tool for improving embryo selection. Improvement of embryo selection will only advocate for the production of clinic-specific embryo kinetic models for prediction of success. The more models of embryo selection we create, the more we may understand whether an optimal morphokinetic profile exists. AIMS: Primary aim: To investigate the comparison with fresh and vitrified/warmed oocytes, using TLS imaging, as well as creating a normative range to reference the classification of future embryo developments. Secondary aim: To investigate the embryo development time lapse (TL) time points of sibling oocytes of patients having both fresh and vitrified oocytes used for treatment in the same insemination cycle. MATERIALS AND METHODS: Retrospective study conducted from 2013 to 2017 at Wijnland Fertility Clinic on de-identified, aggregated TL patient oocyte and embryo development data. Data was filtered according to exclusion and inclusion criteria. Statistical analysis rendered descriptive statistics, quantile (median) regression tests, TOST tests, and matched design linear regression model tests. RESULTS: Results indicated an overall delay in time points and durations between time-points for the vitrified/warmed oocyte population, when compared to their fresh counterparts. Using the quantile (median) regression model, it was found that almost all vitrified/warmed timings were slower than their fresh counterparts (p<0.05), whereby t5 (p=0.068; 95% CI) and t9 (p=0.106; 95% CI) were not. Using the TOST method, it was found that at the 5% level of equivalence, no time points showed equivalence (p<0.05; 90% CI; 5%). It was found at the 10% level that there was significant non-equivalence for time points tPB2, tPNa, t2, t4, t6, t8, tSC, tSB, tB and tHB (p<0.05; 90%CI; 10%). This indicated that for the times stated for non-equivalence there was a delay in timings within the vitrified/warmed oocyte population. Conversely, also at the 10% level, it was found that there was significant equivalence for time points tPNf, t3, t5, t7, t9+ and tEB (p<0.05; 90%CI; 10%), This indicated that for the time points stated there was no statistically significant difference in timings with regards to the fresh and vitrified/warmed oocyte population. Lastly, for the sibling oocyte study, there were no consistent patterns found. This was due to the small population size (n=57). CONCLUSION: In conclusion, this study showed that there was a statistically significant overall delay within the timings for vitrified/warmed oocytes when compared to their fresh counterparts. The most statistically significant findings within this study include the delayed vitrified/warmed oocyte time points for tPNa, t2, t4, t8, tSC, tSB and tHB (p<0.05). The most significant clinical finding of this study was the assumption that vitrified/warmed oocytes undergo mitochondrial stress post warming and requires 2-3 hours of culture in order to reboot the cellular machinery to full operating potential. As a result of this assumption it was suggested that vitrified/warmed oocytes exhibit a 1-hour insemination delay in order to give opportunity for mitochondrial recovery post warming. Another crucial finding was that there was a total delay in the vitrified/warmed oocyte population of 8,53 hours, which could lead to the assumption that even though there was a statistically significant lag exhibited within the vitrified/warmed oocyte population, this is most probably not of clinical significance.en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: AGTERGROND: Infertiliteit word gedefinieer as ‘n afwyking van die voortplantingsstelsel, waar daar versuim word om ‘n kliniese swangerskap te behaal na ‘n periode van 12 maande of langer met gereelde onbeskermde seksuele omgang. Die primêre doelwit van Geassisteerde Reproduktiewe Tegnologie (ART) is om bevrugting te bewerkstellig in gevalle waar natuurlike bevrugting onsuksesvol is. In die afgelope drie dekades het die voorkoms van infertiliteit wêreldwyd betekenisvol toegeneem. Studies, in eerste-wêreld lande, toon dat al hoe meer vrouens uitstel om ‘n familie te begin tot later in hul voorplantingsjare. Hierdie tendens, in terme van vertraging van moederskap, het dus gelei tot die algemene gebruik van oösiet preserveringstegnieke. Die sukses en waarde van oösiet preserveringstegnieke en -metodes is bevestig deur die uitkoms van in vitro bevrugting/intrasitoplasmatiese sperm inspuiting [IVB/ICSI] sukses tussen vars oösiet en gevriesde/ontdooide oösiet siklusse te vergelyk. Hierdie studies toon dat daar geen verskille in die bevrugtings-, implanterings- en swangerskapsyfer is, wanneer vars met gevriese/ontdooide oösiete vergelyk word nie. Daar is huidiglik ook ‘n neiging om die implementering van morfokinetieseanalise te gebruik om die vergelyking van vars en gevriese/ontdooide oösiete te ondersoek. Die toename in tegnologiese verwikkelinge binne die mediese ART veld, dui “time lapse systems” (TLS) aan as ‘n unieke en belowende hulpmiddel vir die verbetering van embrioseleksie. Die beskikbare TLS morfokinetiese data kan lei tot beter embrioseleksie. Kliniek spesifieke TLS morfokinetiese modelle kan moontlik gebruik word vir beter voorspelling van ART sukses. Die ontwikkeling van verskeie verskillende TLS modelle van embrio seleksie, sal toenemend beter insig gee in terme van ‘n optimale morfokinetiese profiel. DOELWITTE: Primêre doelwit: Om die verskil tussen vars en gevriesde/ontdooide oösiet ontwikkeling te ondersoek deur gebruik te maak van TLS morfokinetiese beelde; en ook om verwysingsdata wat normale waardes identifiseer as verwysing en klasifikasie vir toeomstige embriostudies uit te wys. Sekondêre doelwit: Om TL morfokinetiese tydpunte van geneties verwante oösiete van pasiënte wat beide vars en gevriesde/ontdooide oösiete gebruik het vir behandeling in dieselfde inseminasie siklus, te ondersoek . MATERIALE EN METODES: Retrospektiewe studie op anonieme, saamgevoegde TL pasiënt oösiete en embrio ontwikkelingsdata vanaf 2013 tot 2017 by Wijnland Fertiliteitskliniek. Die data is gefiltreer volgens die uitsluitings- en insluitingskriteria voor statistiese analise. Statistiese analise het beskrywende statistiek, kwantielverhouding (mediaan) toetse, TOST toetse, asook ooreenstemmende ontwerp lineêre regressie model toetse ingesluit. RESULTATE: Die resultate van die studie het ‘n algemene vertraging in tydpunte en tydsverloop tussen verskeie tydsperiodes vir die gevriesde/ontdooide oösiet populasie in vergelyking met die vars oösiet populasie aangedui. Die statistiese kwantielverhouding (mediaan) regressie model het bevind dat amper alle gevriesde/ontdooide oösiet tydpunte stadiger was as die vars oösiete tydpunte (p<0.05), uitsluitend t5 (p=0.068; 95% CI) en t9 (p=0.106; 95% CI). Die TOST metode het bevind dat by ‘n 5% vlak van ekwivalensie, geen tydpunt ekwivalent (p<0.05; 90% CI; 5%) was nie. Daar was egter bevind dat by die 10% vlak ekwivalensie, daar beduidende nieekwivalensie was vir die volgende tydpunte: tPB2, tPNa, t2, t4, t6, t8, tSC, tSB, tB en tHB (p<0.05; 90% CI; 10%). In gevalle van nie-ekwivalensie was daar dus ‘n vertraging in die tydpunte van die gevriesde/ontdooide oösiet populasie. Daar was egter ook beduidende ekwivalensie by die 10% vlak vir sekere tydpunte: tPNf, t3, t5, t7, t9+ en tEB (p<0.05; 90% CI; 10%) wat aandui dat vir hierdie tydpunte daar geen beduidende verskil was tussen vars en gevriesde/ontdooide oösiet populasies nie. Ten slotte, vir die geneties verwante oösiet pasïent groep was daar geen betroubare uitkomste nie omdat die groep te klein was vir betroubare statistiese ontleding (n=57). GEVOLGTREKKING: Die navorsing dui daarop daar ‘n algemene, statistiese beduidende vertraging van die morfokinetiese TL tydpunte vir gevriesde/ontdooide oösiete is wanneer dit vergelyk word met vars oösiet tydpunte. Veral beduidend was die vertraging van gevriesde/ontdooide tydpunte; tPNa, t2, t4, t8, tSC, tSB en tHB (p<0.05). Van kliniese waarde is die moontlikheid dat die vertraging in tydpunte van gevriesde/ontdooide oösiete daarop dui dat hierdie oösiete mitokondriale spanning na ontdooing ondervind en dus 2-3 uur langer in kultuur gehou moet word om sellulêre meganismes tot hul volle potensiaal te aktiveer en te laat herstel. As gevolg van dié aanname, word daar voorgestel dat gevriesde/ontdooide oösiete ‘n 1-uur inseminasie vertraging vergun moet word; om die geleentheid te bied vir mitochondriale herstelling na ontdooing. Die bevinding dat daar ‘n algehele vertraging van 8,53 uur in embrioontwikkeling was in die gevriesde/ontdooide oösiet populasies was statisties beduidend , maar heel moontlik nie van kliniese belang nie.af_ZA
dc.format.extentxv, 197 pages : illustrationsen_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch University.en_ZA
dc.subjectFertilization in vitroen_ZA
dc.subjectEmbryologyen_ZA
dc.subjectReproductive Technologyen_ZA
dc.subjectHuman reproductive technologyen_ZA
dc.subjectTime-lapse Systems (TLS)en_ZA
dc.subjectMorphokineticsen_ZA
dc.subjectOocyteen_ZA
dc.subjectVitrificationen_ZA
dc.subjectUCTD
dc.titleTime-lapse analysis and morphokinetic evaluation of fresh vs. vitrified/warmed oocytes, including donor and explorative sibling oocyte cyclesen_ZA
dc.typeThesisen_ZA
dc.description.versionMastersen_ZA
dc.rights.holderStellenbosch University.en_ZA


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