The Ratio of Mitochondrial DNA to Genomic DNA Copy Number in Cumulus Cell May Serve as a Biomarker of Embryo Quality in IVF Cycles.

Previous studies have reported that the mitochondrial DNA (mtDNA) contents of cumulus cells (CCs) in ovarian follicular fluid are correlated with embryo quality. Quantification of mtDNA CCs has been suggested as a biomarker of embryo viability. The aim of this study was to determine the relationship between mitochondrial DNA (mtDNA)/genomic DNA (gDNA) ratio in CCs and IVF outcomes such as fertilization rates and embryo quality in infertile women. This is an observational study on 144 cumulus-oocyte complexes obtained from 144 patients undergoing IVF-intracytoplasmic sperm injection (ICSI) at a single fertility center. The CCs in ovarian follicular fluid from patients undergoing IVF-ICSI were collected by ovum pick-up. A relative copy number quantification was used to determine mtDNA/gDNA ratio. Quantitative real-time PCR for various markers (ß2M and mtMinArc gene) was used to determine average mtDNA/gDNA ratio of CCs. Investigation of the correlation between mtDNA/gDNA ratio in CCs and IVF outcomes showed no statistically significant correlation between the mtDNA/gDNA ratio in CCs and fertilization rates. However, mtDNA/gDNA ratio and embryo quality showed a statistically significant positive correlation. A significantly higher mtDNA/gDNA ratio was observed in the good quality embryo group compared with the poor quality embryo group (P < 0.05). In addition, the mtDNA/gDNA ratio showed negative correlation with the patient's age (correlation coefficient= -0.228, P < 0.05). Results of this study demonstrate a negative correlation of mtDNA/gDNA ratio in CCs with patient's age, and a low copy number of mtDNA in CCs may have adverse effects on embryo quality in IVF cycles. These results suggest that the ratio of mtDNA/gDNA in CCs may serve as a biomarker in predicting IVF outcomes.

Does duration of cryostorage affect survival rate, pregnancy, and neonatal outcomes? Large-scale single-center study of slush nitrogen (SN2 ) vitrified-warmed blastocysts.

OBJECTIVE: To evaluate the effects of the duration of cryostorage on clinical outcomes after embryo transfer of vitrified blastocysts stored in an open-device slush-nitrogen (SN2 ) system. METHODS: A retrospective cohort study was carried out on 1632 autologous vitrified-warmed blastocyst transfer cycles between January 2013 and June 2014. Duration of cryostorage was divided into four groups: Group I: 0-6 months (n=937); Group II: 7-12 months (n=299); Group III: 13-24 months (n=165); and Group IV: ≥25 months (n=231). The effects of the duration of cryostorage on the survival rate (SR), clinical pregnancy rate (CPR), live birth rate (LBR), and neonatal outcomes of vitrified blastocysts stored in an open-device SN2 system were evaluated. RESULTS: There were no significant differences between groups in SR, CPR, LBR, and neonatal outcomes after autologous vitrified-warmed blastocyst transfer. Multivariate logistic regression analysis showed no effect on LBR from duration of cryostorage. CONCLUSION: Vitrification using SN2 and long-term cryostorage in an open-device system are safe and effective and do not significantly affect clinical outcomes after embryo transfer.

Effects and pregnancy outcomes of L-carnitine supplementation in culture media for human embryo development from in vitro fertilization.

AIM: Antioxidants have been studied to be effective in improving embryo qualities from in vitro fertilization. L-carnitine (LC) has been known to reduce reactive oxygen species and enhance adenosine triphosphate production, which contribute to the development of a high-quality embryo. This is the first study to include both mouse and human subjects and aimed to evaluate whether LC supplementation in culture media has any beneficial effect on the development of the embryos, as well as its clinical outcomes. METHODS: Mouse embryos were used as models in the animal studies for cell immunofluorescent staining evaluation. Inner cell mass and trophectoderm (TE) cells were counted and statistically analyzed between LC and control groups. For human studies, medical records of patients with infertility undergoing in vitro fertilization procedures from January to May 2017 were included and the embryos were divided into two groups at the two pronuclear stage. Statistical analysis was performed to compare the embryo status and clinical outcomes of the two groups. RESULTS: In the animal study, the LC group showed significantly higher numbers of cells in the inner cell mass and trophectoderm, indicating better development. In the human studies, there were significantly higher numbers of good-quality embryos on days 2, 3 and 5 in the LC group than in the control. The clinical outcomes, such as implantation, clinical pregnancy and ongoing pregnancy rates, were also higher in the LC group than in the control. CONCLUSION: LC supplementation in culture media improved human embryo quality and eventually achieved better pregnancy outcomes.

Clinical outcomes of single versus double blastocyst transfer in fresh and vitrified-warmed cycles.

OBJECTIVE: Assisted reproductive technology has been associated with an increase in multiple pregnancies. The most effective strategy for reducing multiple pregnancies is single embryo transfer. Beginning in October 2015, the National Supporting Program for Infertility in South Korea has limited the number of embryos that can be transferred per in vitro fertilization (IVF) cycle depending on the patient's age. However, little is known regarding the effect of age and number of transferred embryos on the clinical outcomes of Korean patients. Thus, this study was performed to evaluate the effect of the number of transferred blastocysts on clinical outcomes. METHODS: This study was carried out in the Fertility Center of CHA Gangnam Medical Center from January 2013 to December 2014. The clinical outcomes of 514 women who underwent the transfer of one or two blastocysts on day 5 after IVF and of 721 women who underwent the transfer of one or two vitrified-warmed blastocysts were analyzed retrospectively. RESULTS: For both fresh and vitrified-warmed cycles, the clinical pregnancy rate and live birth or ongoing pregnancy rate were not significantly different between patients who underwent elective single blastocyst transfer (eSBT) and patients who underwent double blastocyst transfer (DBT), regardless of age. However, the multiple pregnancy rate was significantly lower in the eSBT group than in the DBT group. CONCLUSION: The clinical outcomes of eSBT and DBT were equivalent, but eSBT had a lower risk of multiple pregnancy and is, therefore, the best option.