• Clinical and Experimental Reproductive Medicine
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• v.50 no.3
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• pp.177-184
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• 2023

Objective: Reconstructed oocytes after polar body genome transfer constitute a potential therapeutic option for patients with a history of embryo fragmentation and advanced maternal age. However, the rescue of genetic material from the first polar body (PB1) through introduction into the donor cytoplasm is not yet ready for clinical application. Methods: Eighty-five oocytes were obtained following in vitro maturation (IVM) and divided into two groups: PB1 nuclear transfer (PB1NT; n=54) and control (n=31). Following enucleation and PB1 genomic transfer, PB1 fusion was assessed. Subsequently, all fused oocytes underwent intracytoplasmic sperm injection (ICSI) and were cultured in an incubator under a time-lapse monitoring system to evaluate fertilization, embryonic morphokinetic parameters, and cleavage patterns. Results: Following enucleation and fusion, 77.14% of oocytes survived, and 92.59% of polar bodies (PBs) fused. However, the normal fertilization rate was lower in the PB1NT group than in the control group (56.41% vs. 92%, p=0.002). No significant differences were observed in embryo kinetics between the groups, but a significant difference was detected in embryo developmental arrest after the four-cell stage, along with abnormal cleavage division in the PB1NT group. This was followed by significant between-group differences in the implantation potential rate and euploidy status. Most embryos in the PB1NT group had at least one abnormal cleavage division (93.3%, p=0.001). Conclusion: Fresh PB1NT oocytes successfully produced normal zygotes following PB fusion and ICSI in IVM oocytes. However, this was accompanied by low efficiency in developing into cleavage embryos, along with an increase in abnormal cleavage patterns.

• Journal of Embryo Transfer
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• v.27 no.2
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• pp.113-119
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• 2012

Epigenetic modification including genome-wide DNA demethylation is essential for normal embryonic development. Insufficient demethylation of somatic cell genome may cause various anomalies and prenatal loss in the development of nuclear transfer embryos. Hence, the source of nuclear donor often affects later development of nuclear transfer (NT) embryos. In this study, appropriateness of porcine embryonic germ (EG) cells as karyoplasts for NT with respect to epigenetic modification was investigated. These cells follow methylation status of primordial germ cells from which they originated, so that they may contain less methylated genome than somatic cells. This may be advantageous to the development of NT embryos commonly known to be highly methylated. The rates of blastocyst development were similar among embryos from EG cell nuclear transfer (EGCNT), somatic cell nuclear transfer (SCNT), and intracytoplasmic sperm injection (ICSI) (16/62, 25.8% vs. 56/274, 20.4% vs. 16/74, 21.6%). Genomic DNA samples from EG cells (n=3), fetal fibroblasts (n=4) and blastocysts from EGCNT (n=8), SCNT (n=14) and ICSI (n=6) were isolated and treated with sodium bisulfite. The satellite region (GenBank Z75640) that involves nine selected CpG sites was amplified by PCR, and the rates of DNA methylation in each site were measured by pyrosequencing technique. The average methylation degrees of CpG sites in EG cells, fetal fibroblasts and blastocysts from EGCNT, SCNT and ICSI were 17.9, 37.7, 4.1, 9.8 and 8.9%, respectively. The genome of porcine EG cells were less methylated than that of somatic cells (p<0.05), and DNA demethylation occurred in embryos from both EGCNT (p<0.05) and SCNT (p<0.01). Interestingly, the degree of DNA methylation in EGCNT embryos was approximately one half of SCNT (p<0.01) and ICSI (p<0.05) embryos, while SCNT and ICSI embryos contained demethylated genome with similar degrees. The present study demonstrates that porcine EG cell nuclear transfer resulted in hypomethylation of DNA in cloned embryos yet leading normal preimplantation development. Further studies are needed to investigate whether such modification affects long-term survival of cloned embryos.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.439-449
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• 2000

This study was to investigate the expression of transgene after co-injection of spermatozoon and EGFP gene into mature oocytes in cattle. From frozen semen, spermatozoa were treated by DTT with 0.03% Tween-20, freezing and thawing or 0.02% Triton X-100 to disrupt their plasma membranes. The sperm injected oocytes were co-cultured with bovine oviduct epithelial cells in CRlaa, and expression of EGFP in embryos were observbed under epifluorescent microscope. Two pronuclei were formed in oocytes injected with sperm treated by DTT (44.6%), DTT-Tween-20 (48.4%), DTT-freezing (44.4%) and DTT-Triton X-100 (42.9%). Cleavage and blastocyst formation rates of bovine oocytes which injected with sperm treated by DTT, DTT-Tween-20, DTT-freezing, and DTT-Triton X-100 were 49.1, 58.5, 43.9, and 48.4% and 10.2, 13.0, 6.8, and 6.5%, respectively. Although the most of embryos were showing mosaicism, embryos expressing EGFP gene were observed in all treated groups. Therefore, these results indicate that membrane disrupted sperm could interact with exogenous DNA, and that this procedure may be useful to introduce foreign gene into bovine oocytes.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.1
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• pp.41-48
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• 2007

Objective: To determine whether the presence of Y-chromosome microdeletion affects the outcome of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) program. Methods: Fourteen couples with microdeletion in azoospermic factor (AZF)c region who attempted IVF/ICSI or cryopreserved and thawed embryo transfer cycles were enrolled. All of the men showed severe oligoasthenoteratoazoospermia (OATS) or azoospermia. As a control, 12 couples with OATS or azoospermia and having normal Y-chromosome were included. Both groups were divided into two subgroups by sperm source used in ICSI such as those who underwent testicular sperm extraction (TESE) and those used ejaculate sperm. We retrospectively analyzed our database in respect to the IVF outcomes. The outcome measures were mean number of good quality embryos, fertilization rates, implantation rates, $\beta$-hCG positive rates, early pregnancy loss and live birth rates. Results: Mean number of good quality embryos, implantation rates, $\beta$-hCG positive rates, early pregnancy loss rates and live birth rates were not significantly different between Y-chromosome microdeletion and control groups. But, fertilization rates in the Y-chromosome microdeletion group (61.1%) was significantly lower than that of control group (79.8%, p=0.003). Also, the subgroup underwent TESE and having AZFc microdeletion showed significantly lower fertilization rates (52.9%) than the subgroup underwent TESE and having normal Y-chromosome (79.5%, p=0.008). Otherwise, in the subgroups used ejaculate sperm, fertilization rates were showed tendency toward lower in couples having Y-chromosome microdeletion than couples with normal Y-chromosome. (65.5% versus 79.9%, p=0.082). But, there was no significance statistically. Conclusions: In IVF/ICSI cycles using TESE sperm, presence of V-chromosome microdeletion may adversely affect to fertilization ability of injected sperm. But, in cases of ejaculate sperm available for ICSI, IVF outcome was not affected by presence of Y-chromosome AZFc microdeletion. However, more larger scaled prospective study was needed to support our results.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.225-232
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• 1997

폐색성 혹은 비폐색성 무정자증에서 부정소 정자채취법 등이 부적절하다고 여겨질때는 정소 조직을 일부 절제하여 그 조직으로부터 정자를 직접 채취하게 되는데 일반적으로 이렇게 정소로부터 추출한 정소정자는 운동성이 전혀 없거나 매우 약한 운동성을 보이는 경우가 많다. 본 연구의 목적은 이러한 정소정자를 Vero cell과 공배양을 시킴으로써 운동성을 획득시키거나 향상시키고 이를 수정시키는 시기까지 지속시킴으로써 정소정자추출술 (TESE)을 시행하는 환자나 의료진들에게 보다 편안하고 융통성있는 시간대를 부여하고, 아울러 정자직접주입술 (ICSI)을 보다 용이하게 하여 성공적인 수정률과 임신율을 얻음에 있다. 또한 ICSI를 시행한 후, 운동성이 향상된 잉여의 정소정자를 냉동보존함으로써 차후에 TESE을 다시 시행치않고도 시험관 아기 시술을 시도할 수 있는 부가적인 잇점도 있다고 할 수 있다. 대상환자군은 정관폐색증(n=11) 혹은 비정관폐색증(n=2)을 보이는 13명의 무정자증의 남성불임환자였으며 난자회수예정일 3일전에 TESE를 시행하여 정소정자를 얻은 후 이를 정자직접주입술이 시행되는 당일까지 Vero cell과 공배양을 실시하였다. Vero cell과의 공배양에 의하여 운동성이 있는 정소정자의 수는 공배양전과 비교하여 평균 3.3배가 증가하였으며, 특히 공배양전에 운동성이 있는 정소정자의 수가 50,000/ml이하의 미약한 운동성만을 보였던 경우 (n=5)에는 공배양 후에 운동성이 있는 정소정자 수의 평균증가율이 7.7배였다. 공배양전 정자운동성이 전혀 없었던 2례의 비정관폐색증환자중 3일간의 공배양을 통하여 1례에서 운동성을 획득한 정소정자를 얻을 수 있었으며 (14,300/ml), 정자직접주입술을 통하여 성공적인 수정 및 임신에 도달할 수 있었다. Vero cell과 공배양을 하고 ICSI했던 결과, 평균 수정률은 75.0% 이었으며 임신율은 61.5%였다.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.3
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• pp.323-329
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• 1998

The safety of ICSI as a novel procedure of assisted fertilization may be assessed by the health of the baby born. In order to evaluate the safety of ICSI, perinatal outcome and congenital anomaly of the babies born after ICSI were compared with those of babies born after IVF (control group). We analysed the clinical data from the obstetric and pediatric records, including the information obtained through telephone. The results are as follows; Mean gestational age $({\pm}SEM)$ and birth weight in singleton pregnancy were $38.8{\pm}1.9$ weeks and $3209.7{\pm}501.9gm$ in IVF group, $39.0{\pm}2.2$ weeks and $3289.9{\pm}479.5gm$ in ICSI group, respectively. Mean gestational age and birth weight in twins were $36.8{\pm}2.1$ weeks and $2512.8{\pm}468.0gm$ in IVF group, $36.5{\pm}2.8$ weeks and $2492.7{\pm}537.1gm$ in ICSI group. In IVF group, perinatal mortality rates were 8.5 in singletons and 56.6 in twins; for the ICSI singletons and ICSI twins, the perinatal mortality rates were 11.6 and 49.0, respectively. The incidence of congenital malformations was 3.6% (8/224) in IVF group and 2.1% (4/188) in ICSI group, there was no statistical difference (p>0.05, Fisher's exact test). The incidence of major congenital anomalies was 0.9% (2/224; pulmonary artery hypoplasia, renal cystic dysplasia) in IVF group and 1.1% (2/188; holoprosencephaly, Cri du chat syndrome) in ICSI groups (p>0.05, Fisher's exact test). Similarly, there was no significant difference in incidence of minor congenital anormalies 2.7% (6/224) in IVF group and 1.1% (2/188) in ICSI group respectively (p>0.05, Fisher's exact test). In conclusion, there was no difference in the perinatal outcome and the incidence of congenital anomalies between the babies born after ICSI and those after conventional IVF.

• Journal of Embryo Transfer
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• v.23 no.1
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• pp.19-24
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• 2008

The purpose of this study was to compare the efficiency of slow freezing with that of vitrification method for the cryopreservation of human embryos. Human embryos were derived from in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and the mixed solution of propanedial (1.5, 1.0, 0.5M PROH) and sucrose (0.1M), ethylene glycol (7.5, 15%), dimethyl sulfoxide (7.5, 15% DMSO), sucrose (0.5, 1.0M) and SPS (Serum Protein Substitute) was used for a cryoprotectant for slow freezing and vitrification solution, respectively. Rates of recovery after thawing, morphological normality, post-thaw viability, arrest, morphological abnormality and preimplantation development were compared between two protocols. After freezing-thawing, recovery and survial rate of slow freezing was (88.6% and 73.4%), whereas vitrification was (99.2% and 96.2%) (p<0.05). The arrest rate of slow freezing was significantly lower compared with those of vitrification(8.7% vs 29.9%) (p<0.05). Preimplantation development to the 2-cell (83.8% vs 67.7%), 4-cell (69.0% vs 47.2%) and 8-cell (62.4% vs 37.8%) stages 24, 48 and 72 h after thawing, respectively, were higher in the slow freezing than the vitrification. After slow freezing and vitrification of human embryo at 2-8cell stage, the rate of recovery rate, survival rate and partial damage rate were 92.0% vs 100%, 80.4% vs 96.2% and 52.2% vs 19.0%, respectively. And partial damage rate was significantly lower than those of slow freezing method (p<0.05). These results demonstrate that a slow freezing using PROH is more efficient than a vitrification for cryopreserving the human zygotes, although the vitrification yielded better recovery, survival and partial damage of frozen-thawed 2-8 cell stage embryos than slow freezing method.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.228-233
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• 2011

Objective: To investigate the effectiveness of GnRH antagonist multiple-dose protocol (MDP) with oral contraceptive pill (OCP) pretreatment in poor responders undergoing IVF/ICSI, compared with GnRH antagonist MDP without OCP pretreatment and GnRH agonist low-dose long protocol (LP). Methods: A total of 120 poor responders were randomized into three groups according to controlled ovarian stimulation (COS) options; GnRH antagonist MDP after OCP pretreatment (group 1), GnRH antagonist MDP without OCP pretreatment (group 2) or GnRH agonist luteal low-dose LP without OCP pretreatment (group 3). Patients allocated in group 1 were pretreated with OCP for 21days in the cycle preceding COS, and ovarian stimulation using recombinant human FSH (rhFSH) was started 5 days after discontinuation of OCP. Results: There were no differences in patients' characteristics among three groups. Total dose and days of rhFSH used for COS were significantly higher in group 3 than in group 1 or 2. The numbers of mature oocytes, fertilized oocytes and grade I, II embryos were significantly lower in group 2 than in group 1 or 3. There were no significant differences in the clinical pregnancy rate and implantation rate among three groups. Conclusion: GnRH antagonist MDP with OCP pretreatment is at least as effective as GnRH agonist low-dose LP in poor responders and can benefit the poor responders by reducing the amount and duration of FSH required for follicular maturation.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.4
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• pp.163-168
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• 2015

Objective: To investigate the impact of fibroids on the blood flow of the uterine and subendometrial arteries and in vitro fertilization (IVF) outcomes. Methods: In this study, we analyzed 86 IVF/intracytoplasmic sperm injection (ICSI) cycles in which a gonadotropin-releasing hormone antagonist protocol was used for controlled ovarian stimulation between January 2008 and March 2009. The subjects comprised 86 infertile women with (fibroid group, n=43) or without (control group, n=43) uterine fibroids. Results: Patient characteristics were similar between the fibroid and control groups. The IVF/ICSI outcomes in patients with fibroids were similar to those of patients in the control group. The resistance index (RI) and pulsatile index (PI) of the uterine and subendometrial arteries on the day of embryo transfer were also comparable between the two groups. IVF outcomes and uterine hemodynamics in patients with multiple (${\geq}2$) fibroids were similar to those of patients with a single fibroid. However, clinical pregnancy and implantation rates were significantly lower in patients with fibroids who experienced uterine cavity distortion than in patients with fibroids who had a normal uterine cavity (both p<0.05). The RI and PI of the subendometrial artery were significantly higher on the day of embryo transfer in patients with fibroids who experienced uterine cavity distortion than in patients with fibroids who had a normal uterine cavity (both p<0.05). Conclusion: Fibroids which distorting the uterine cavity might impair the subendometrial artery blood flow clinical pregnancy rate and embryo implantation rate in infertile patients undergoing IVF. Otherwise, IVF outcomes were not influenced by the presence of uterine fibroids.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.4
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• pp.149-155
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• 2015

Objective: The goal of this study was to investigate the relationship between serum progesterone (P4) levels on the day of human chorionic gonadotropin (hCG) administration and the pregnancy rate among women undergoing controlled ovarian stimulation for in vitro fertilization (IVF) or intracytoplasmic sperm injection-embryo transfer (ICSI-ET) using a flexible antagonist protocol. Methods: This prospective study included 200 IVF and ICSI-ET cycles in which a flexible antagonist protocol was used. The patients were divided into five distinct groups according to their serum P4 levels at the time of hCG administration (0.80, 0.85, 0.90, 0.95, and 1.00 ng/mL). The clinical pregnancy rate (CPR) was calculated for each P4 interval. Statistically significant differences were observed at a serum P4 level of 0.9 ng/mL. These data suggest that a serum P4 concentration of 0.9 ng/mL may represent the optimal threshold level for defining premature luteinization (PL) based on the presence of a significant negative impact on the CPR. Results: The CPR for each round of ET was significantly lower in the PL group defined using this threshold (25.8% vs. 41.8%; p=0.019), and the number of oocytes retrieved was significantly higher than in the non-PL group ($17.3{\pm}7.2$ vs. $11.0{\pm}7.2$; p=0.001). Elevated serum P4 levels on the day of hCG administration were associated with a reduced CPR, despite the retrieval of many oocytes. Conclusion: Measuring serum P4 values at the time of hCG administration is necessary in order to determine the optimal strategy for embryo transfer.