Department of Obstetrics and Gynaecology

Permanent URI for this community

https://scholar.sun.ac.za/handle/10019.1/166

Browse

Browsing Department of Obstetrics and Gynaecology by browse.metadata.advisor "Els-Smit, Lydia"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Effect of human male patient diagnosis on syngamy timing and blastulation using time-lapse technology
    (Stellenbosch : Stellenbosch University, 2019-04) Steyn, Cheyenne; Windt De Beer, Marie-Lena; Els-Smit, Lydia; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Obstetrics and Gynaecology.
    BACKGROUND: Improving embryo selection for embryo transfer is essential in Assisted Reproductive Technologies (ART), especially in single embryo transfer settings to reduce multiple birth rate. Current selection methods are largely based on assessment of morphological characteristics. Morphological blastocyst parameters have been shown in literature to correlate with implantation and live birth success rates, while female age is well established to affect overall assisted reproductive technology outcomes. More recently, kinetic parameters from time lapse (TL) technology have also emerged as additional selection characteristics during embryo development. As of yet, the effect of certain patient factors on kinetic parameters is to be elucidated. Syngamy is the merging event of maternal and paternal deoxyribonucleic acid (DNA) during fertilization and can be accurately determined / visualized using TL. The functional centrosome within the spermatozoa contributes to chromosome alignment and combination, therefore possibly impacting syngamy. The paternal genome from the spermatozoon also possibly contributes to blastulation on day 5 of embryo development by playing a role in the embryo genome activation, which drives advanced embryo development. The kinetic time points generated by TL technology during embryo development, can be used to examine the potential effect of male fertility diagnosis on syngamy and blastulation. This may elucidate whether syngamy timing is a relevant kinetic parameter that can allow more accurate selection and prediction of good quality embryos. AIMS: Primary aim: To investigate the possible measurable direct effect of male fertility prognosis using TL, on the time duration to the syngamy fertilization event. Secondary aim: To investigate the subsequent effect of male fertility prognosis using TL, on syngamy timing and the resulting advanced embryo development and blastocyst quality. MATERIALS AND METHODS: This was a retrospective study that was conducted from 2017 to 2018 at Wijnland Fertility clinic on de-identified, aggregated TL patient embryo data from 2013 to 2016. Data was filtered according to inclusion and exclusion criteria and categorized according to defined male prognosis groups (good prognosis (GP), poor prognosis (PP), and very poor prognosis (VP)). Data was submitted for statistical analysis (statistical significance: P < 0.05). Female age was compensated for during statistical analysis. RESULTS: Results indicated that all three male prognosis groups (GP, PP, VP) had similar rates of normal fertilization (60.12%, 58.84%, and 54.29%, P = 0.19) and subsequent blastulation (64.75%, 69.61%, and 63.28%, P = 0.25). The GP group showed significantly shorter syngamy timing compared to the VP group (19.73 ± 3.69 hours vs 20.80 ± 4.71 hours, P = 0.02). Shorter syngamy timing significantly correlated with increased blastocyst expansion on day 5 of embryo development in all groups (P < 0.01). A shorter syngamy timing significantly correlated with A-grade trophectoderm epithelium (TE) quality compared to B-grade (P = 0.02). A-grade TE in the GP group (P = 0.05) and VP group showed significantly shorter syngamy timing compared to B-grade in the VP group (P =0.04). Syngamy timing did not show any significant correlation with inner cell mass (ICM) quality (P = 0.36) or between male prognosis groups (P = 0.13). CONCLUSION: Results indicated that although fertilization and blastulation rate amongst the male prognosis groups were similar, poorer male prognosis may lead to extended syngamy timing and poorer blastocysts, impacting expansion and trophectoderm epithelium quality specifically. Since these two blastocyst parameters are the most important indicators of embryo implantation potential, syngamy can therefore be an early predictive marker for blastocyst quality, irrespective of initial sperm prognosis.
  • Thumbnail Image
    Item
    Time-lapse analysis and morphokinetic evaluation of fresh vs. vitrified/warmed oocytes, including donor and explorative sibling oocyte cycles
    (Stellenbosch : Stellenbosch University., 2020-03) Ramsay, Dylan; Windt De Beer, Marie-Lena; Van Waart, Johannes; Els-Smit, Lydia; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Obstetrics and Gynaecology.
    ENGLISH 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.