San Hyun Yoon

Kangwon National University, Shunsen, Gangwon, South Korea

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Publications (8)7.29 Total impact

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    ABSTRACT: The aim of this study was to evaluate the efficiency of the intracytoplasmic morphologically selected sperm injection (IMSI) technique compared with conventional ICSI and previous ICSI attempts in oligo-astheno-teratozoospermia (OAT) patients. The sperms were selected under high magnification (6,600×) and used to induce fertilization in previous ICSI patients by IMSI. These results were compared with previous conventional ICSI cycles in patients with OAT infertility. These results demonstrated no significant difference in the fertilization rate between IMSI and previous ICSI cycles (67.7% vs. 65.0%). However, the pregnancy and implantation rates with IMSI were significantly higher than those of the ICSI cycles (33.3% vs. 12.5% and 14.6% vs. 5.4%, respectively; p<0.05). The miscarriage rate among pregnant patients (18.2% vs. 37.5%) showed no statistically significant difference between groups. Compared to conventional ICSI, this study found that IMSI increased the IVF-ET success rates in patients with OAT.
    Clinical and experimental reproductive medicine. 03/2014; 41(1):9-14.
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    ABSTRACT: Fertilization failures have occurred repeatedly in reproductive centers after intracytoplasmic sperm injection (ICSI) and artificial oocyte activation (AOA) has been used to prevent it. This study was performed to investigate whether spermatozoan origin influences clinical outcomes of AOA with a calcium ionophore. A total of 185 ICSI cycles with a history of no or low fertilization was included in this retrospective study. The outcomes of AOA after ICSI were compared with ejaculated-normal, ejaculated-oligo-astheno-terato or extracted-testicular spermatozoa. There were significant differences between the previous standard ICSI cycles and AOA cycles in the rate of fertilization and clinical outcomes among cases with different sperm origins. Thirty-eight healthy babies (20 singles and 18 twins, 29 cycles) were successfully delivered, and no congenital birth defects were observed. Most patients with a no or low fertilization history obtained an increased fertilization rate and a positive clinical outcome with AOA regardless of the origin of spermatozoa.
    Journal of Assisted Reproduction and Genetics 10/2013; · 1.82 Impact Factor
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    ABSTRACT: PURPOSE: To compare the efficacy of single vitrified-warmed blastocyst embryo transfer (SVBT) versus double vitrified-warmed blastocyst embryo transfer (DVBT) according to the day of vitrification. METHODS: This retrospective study included a total of 1,051 cycles in women less than 37 years of age with their autologous SVBT cryopreserved on day 5 (5d-SVBT, n = 737) or day 6 (6d-SVBT, n = 154) and DVBT on day 5 (5d-DVBT, n = 129) or day 6 (6d-DVBT, n = 31) from January 2009 to December 2011. RESULTS: The clinical pregnancy rate (41.8 % vs. 48.1 %, p = 0.184) and ongoing pregnancy rate (36.6 % vs. 45.0 %, p = 0.072) were not significantly different between the 5d-SVBT group and the 5d-DVBT group. However, the clinical pregnancy (29.9 % vs. 58.1 %, p = 0.003) and ongoing pregnancy rates (23.4 % vs. 51.6 %, p = 0.001) were significantly lower in the 6d-SVBT group compared with those in the 6d-DVBT group. The implantation rate (42.2 % vs. 34.5 %, p = 0.03) of the 5d-SVBT group was significantly higher than that of the 5d-DVBT group, while the implantation rate (29.9 % vs. 37.1 %, p = 0.303) of the 6d-SVBT group was not statistically different compared with that in the 6d-DVBT group. The multiple pregnancy rates (1.0 % in the 5d-SVBT group vs. 38.7 % in the 5d-DVBT group, p < 0.001 and 0 % in the 6d-SVBT group vs. 22.2 % in the 6d-DVBT group, p = 0.001) were statistically significantly lower in the SVBT group compared with those in the DVBT group regardless of the day of vitrification. CONCLUSIONS: This study showed that the 5d-SVBT resulted in comparable clinical outcomes compared to the 5d-DVBT while the 6d-SVBT yielded significantly lower clinical outcomes compared to the 6d-DVBT.
    Journal of Assisted Reproduction and Genetics 05/2013; · 1.82 Impact Factor
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    ABSTRACT: PURPOSE: Micro-vibration culture system was examined to determine the effects on mouse and human embryo development and possible improvement of clinical outcomes in poor responders. MATERIALS AND METHODS: The embryonic development rates and cell numbers of blastocysts were compared between a static culture group (n = 178) and a micro-vibration culture group (n = 181) in mice. The embryonic development rates and clinical results were compared between a static culture group (n = 159 cycles) and a micro-vibration culture group (n = 166 cycles) in poor responders. A micro-vibrator was set at a frequency of 42 Hz, 5 s/60 min duration for mouse and human embryo development. RESULTS: The embryonic development rate was significantly improved in the micro-vibration culture group in mice (p < 0.05). The cell numbers of mouse blastocysts were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). In the poor responders, the rate of high grade embryos was not significantly improved in the micro-vibration culture group on day 3. However, the optimal embryonic development rate on day 5 was improved in the micro-vibration group, and the total pregnancy rate and implantation rate were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). CONCLUSIONS: Micro-vibration culture methods have a beneficial effect on embryonic development in mouse embryos. In poor responders, the embryo development rate was improved to a limited extent under the micro-vibration culture conditions, but the clinical results were significantly improved.
    Journal of Assisted Reproduction and Genetics 05/2013; · 1.82 Impact Factor
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    ABSTRACT: The aim of this study was to compare vitrification optimization of mouse embryos using electron microscopy (EM) grid, cryotop, and thin plastic strip (TPS) containers by evaluating developmental competence and apoptosis rates. Mouse embryos were obtained from superovulated mice. Mouse cleavage-stage, expanded, hatching-stage, and hatched-stage embryos were cryopreserved in EM grid, cryotop, and TPS containers by vitrification in 15% ethylene glycol, 15% dimethylsulfoxide, 10 µg/mL Ficoll, and 0.65 M sucrose, and 20% serum substitute supplement (SSS) with basal medium, respectively. For the three groups in which the embryos were thawed in the EM grid, cryotop, and TPS containers, the thawing solution consisted of 0.25 M sucrose, 0.125 M sucrose, and 20% SSS with basal medium, respectively. Rates of survival, re-expansion, reaching the hatched stage, and apoptosis after thawing were compared among the three groups. Developmental competence after thawing of vitrified expanded and hatching-stage blastocysts using cryotop and TPS methods were significantly higher than survival using the EM grid (p<0.05). Also, apoptosis positive nuclei rates after thawing of vitrified expanded blastocysts using cryotop and TPS were significantly lower than when using the EM grid (p<0.05). The TPS vitrification method has the advantages of achieving a high developmental ability and effective preservation.
    Clinical and experimental reproductive medicine. 12/2012; 39(4):153-60.
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    ABSTRACT: To compare the clinical outcomes of elective single morula embryo transfer (eSMET) versus elective single blastocyst embryo transfer (eSBET) in selected patients. This study was a retrospective study which analyzed for 271 cycles in women under 37 years of age who are undergoing their first or second trial of in vitro fertilization-embryo transfer (IVF-ET) from January 2008 to December 2009. The eSMET was performed on day 4 (n = 130) and the eSBET was conducted on day 5 (n = 141). The clinical pregnancy rate (51.5% vs. 51.8%, p = 0.97), implantation rate (52.3% vs. 52.5%, p = 0.98), and live birth rate (39.2% vs. 44.7%, p = 0.36) were similar in the eSMET and eSBET groups, respectively. The miscarriage rate of the eSMET group (23.9%) was slightly higher than that of the eSBET group (13.7%) (p = 0.12), without reaching statistical significance. There was only one case of monozygotic twin pregnancy in each group. The clinical outcomes of day 4 eSMET were comparable to those of day 5 eSBET. Therefore, day 4 eSMET is a viable option or an alternative to day 5 eSBET, with no difference in success rates.
    Journal of Assisted Reproduction and Genetics 03/2012; 29(5):423-8. · 1.82 Impact Factor
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    ABSTRACT: This study aimed to determine the safety and clinical effect of artificial shrinkage (AS) in terms of assisted hatching of fresh blastocysts. Also, we evaluated the correlation between patient age and the effect of AS on clinical outcome. Two AS methods, using a 29-gauge needle and laser pulse, were compared. Seventy-three blastocysts were shrunk using a 29-gauge needle and the same number of other blastocysts were shrunk by a laser pulse. We evaluated the shrunken blastocysts hourly and considered them viable if they re-expanded >70%. Blastocyst transfer cycles (n=134) were divided into two groups: a control group consisted of the cycles whose intact embryos were transferred (n=100), while the AS group consisted of the cycles whose embryos were replaced following AS (n=34). The implantation and pregnancy rates of the control group and AS group were compared (p<0.05). The re-expansion rates of the 29-gauge needle and laser pulse AS groups were similar (56 [76.7%] vs. 62 [84.9%], respectively). All of the remaining shrunken blastocysts were re-expanded within 2 hours. There was no degeneration of shrunken blastocysts. The total and clinical pregnancy rate of the AS group (23 [67.6%]; 20 [58.8%], respectively) was significantly higher than that of the control group (47 [47.0%]; 39 [39.0%], respectively). In the older patient group, there was no difference in the clinical outcomes between the AS and control groups. These results suggest that AS of blastocoele cavity, followed by the transfer, would be a useful approach to improve the clinical outcome in cycles in which fresh blastocyst stage embryos are transferred.
    Clinical and experimental reproductive medicine. 06/2011; 38(2):87-92.
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    ABSTRACT: This study was carried out to compare the clinical outcome of elective single cleavage-embryo transfer (eSCET) to that of elective single blastocyst-embryo transfer (eSBET) in human IVF-ET. This study was a retrospective study which analyzed for 614 women who visited the Daegu Maria Clinic from August 2008 to December 2009. All were under 37 years old and had more than 8 mm of endometrial thickness on the day of hCG administration and at least one good quality embryo on day 3. The eSCETs were performed on day 3 (n=450) and the eSBETs were conducted on day 5 (n=164). The numbers of retrieved oocytes, fertilized oocytes, and day 3 good quality embryos were significantly lower in the eSCET group (12.1±6.0, 8.2±4.6, and 4.2±3.1, respectively) compared to the eSBET group (16.7±7.2, 12.1±5.0, and 8.5±4.5, respectively; p<0.001). However, the clinical pregnancy, implantation, on-going pregnancy, and live birth rates of the eSCET group (46.7, 46.9, 40.0, and 36.7%, respectively) were not statistically different from those of the eSBET group (51.2, 51.8, 45.1, and 43.9%, respectively; p=0.318, 0.278, 0.254, and 0.103, respectively). These results suggested that elective single embryo transfer should be performed regardless of the developmental stage to women less than 37 years old who had more than 8 mm of endometrial thickness on the hCG administration day and at least one good quality embryo on day 3 in order to reduce the twin pregnancy rate without reducing the whole pregnancy rate.
    Clinical and experimental reproductive medicine. 03/2011; 38(1):53-60.

Publication Stats

8 Citations
7.29 Total Impact Points

Institutions

  • 2013
    • Kangwon National University
      Shunsen, Gangwon, South Korea
  • 2011–2013
    • Maria Fertility Hospital
      Sŏul, Seoul, South Korea