• Clinical and Experimental Reproductive Medicine
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• 제24권2호
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• pp.273-277
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• 1997

This case report describes the pregnancy following the transfer of cryopreserved embryos generated from intracytoplasmic sperm injection (ICSI) using frozen-thawed sperm obtained by microepididymal sperm aspiration (MESA) in patient with congenital absence of the vas deferens (CAVD).

• Clinical and Experimental Reproductive Medicine
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• 제20권2호
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• pp.161-164
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• 1993

To forsee appropriate developmental cell stage in human embryos for cryopreservation, we observed blastocyst development in culture medium after cryopreservatlon and thawing of one cell, two cell, four cell stage of mice embryos. According to our results, development of the blastocyst of cryopreserved two cell mice embryos was significantly higher than that of cryopreserved one cell mice zygotes or four cell mice embryos.

• Clinical and Experimental Reproductive Medicine
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• 제27권3호
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• pp.283-289
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• 2000

Objective: The study was performed to compare the survival rate and the development of day 2 mouse embryos which had freezing procedures done. Methods: We used three different vitrification solutions (EFS, VS14, DPS) and a ultrarapid freezing solution (UFS) for cryopreservation of day 2 mouse embryo. Results: We tested toxicity by exposing embryos to vitirification solutions and a ultrarapid freezing solution. The survival rates are 100%, 97.8%, 95.6% and 100% (EFS, VS14, DPS and UFS). After cultured for 96 hours, hatching rates of each group are 93.5% (no freezing), 95.6% (EFS), 86.4% (VS14), 93.0% (DPS), and 93.0% (UFS). There is no significant differences among groups. The survival rates after thawing cryopreserved embryos are 80.2%, 91.7%, 69.5%, 0% and 91.8% (slow freezing, EFS, VS14, DPS and UFS). Also cultured for 96 hours, the hatching rates are 93.5% (no freezing), 84.1% (slow freezing), 93.9% (EFS), 48.5% (VS14) and 70.1% (UFS). Conclusion: The survival rates of vitrification in EFS solution and ultrarapid freezing are higher than slow freezing (p<0.05). The hatching rate of vitrification in EFS solution cultured for 96 hours is highest, so vitrification of day 2 mouse embryos in EFS solution considered as more effective for cryopreservation.

• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.347-353
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• 1997

본 실험은 초자화 동결된 생쥐 배반포기배의 융해 후 배양조건 및 이식방법이 난자의 생존에 미치는 효과를 조사하고자 실시하였다. 체외수정후, M16배양액에서 4일동안 배양하여 얻어진 생쥐 배반포기배는 EFS40 (40% ethylene glycol, 18% Ficoll, 0.5 M sucrose가 함유된 PBS)으로 초자화동결하였다. 실험 I에서는 융해 후 배양조건에 따른 난자들의 체외/체내 생존율을 조사하였다. 융해된 난자가 M16과 4 mg/ml 소혈청알부민과 20 가지 아미노산이 함유된 m-CR1 (2% BME 아미노산 용액, 1% MEM 아미노산 용액) 및 단층배양이 유도된 난구세포 (10% FBS가 함유된 m-CR1배양액)에서 각각 배양되었을 때, 융해 후 24시간째 체외 생존율은 배양조건에 따라 차이가 없었다(75.6, 83.1, 82.4%). 그러나 체내 발달율에 있어서 임신 15일째 생존 산자율은 39.0, 49.0, 38.1%로서 유사한 성적을 나타냈으나, 전체 착상율에 있어서는 m-CR1 (80.4%)에 배양되었을 때, M16 (51.2%), 난구세포와 공배양시 (57.1%)보다 유의하게 높은 생존율을 보였다(p<0.05). 실험 II에서는 수정란 이식 방법에 따른 체내 발달율을 조사하였다. 배반포기배를 융해 후 체외배양없이 곧바로 가임신 2, 3일째 대리모에 이식을 실시하였을 때, 가임신 2일째 대리모에서는 임신징후를 얻지 못하였고, 가임신 3일째 대리모에서는 50.0%의 착상율과 15.4%의 정상산자율을 얻었다. 그러나, 이러한 결과는 융해 후, 16시간 배양하여 가임신 3일째 대리모에 이식 (73.5, 57.1%)하는 경우보다 유의하게 낮은 결과였다(p<0.05). 실험 III에서는 초자화 동결된 배반포기배의 융해 후 배양시 발달이 늦어진 수정란의 이용효율을 극대화시키기 위해 융해한 4일째 초기, 5일째 초기, 5일째 팽창 배반포기배의 체외/체내 생존율을 조사하였다. 가장 높은 체외 생존율은 5일째 팽창 배반포기배 (78.3%)에서 얻었으나, 체내 발달율 (산자율, 착상율)에 있어서는 4일째 초기 배반포기배 (33.3, 66.7%)의 경우가, 5일째 팽창 배반포기배(29.0, 38.7%)의 경우보다 높았다(p<0.05). 따라서 본 연구의 결과는 배양조건과 수정란 이식방법에 따라 초자화 동결된 배아의 체외/체내 발달율을 높일 수 있으며, 발달이 늦은 배반포기배의 체내 발달율은 체외 배양시간이 길어질수록 낮아짐으로, 5일째 팽창 배반포기배보다 4일째 초기 배반포기배를 동결하는 것이 더 유용하다는 것을 알 수 있었다.

• Clinical and Experimental Reproductive Medicine
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• 제28권4호
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• pp.287-293
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• 2001

Objective : To investigate the efficacy of high infusion frequency of liquid nitrogen on pregnancy in human embryo after freezing and thawing. Materials and Methods: 150 infertile patients underwent 162 consecutive thawing-ET cycles. In the high infusion frequency group (Group A), 47 patients (50 cycles) underwent cryopreservation with high infusion frequency of liquid nitrogen. In the low infusion frequency group (Group B), 103 patients (112 cycles) underwent cryopreservation with low infusion frequency of liquid nitrogen. We analyzed the clinical characteristics, fertilization rates, development of embryo, good quality embryo ratio, implantation rates, and pregnancy rates between these two groups. Results: There was no difference between the groups with regard to clinical characteristics (mean age, infertility duration, infertility factors, hormone profile), mean number of oocyte retrieval, fertilization rates, and mean embryo number of transfers. The survival rates in group A was 64.9% (228 of 350 embryos), and among the 228 embryos 190 embryos (83.3%) which progressed to the two- to eight-cell stage. After thawing, the embryo numbers were 65 (34.2%), 29 (15.3%), 35 (18.4%), and 37 (19.5%) of grades 1, 2, 3, and above 4, respectively. The survival rates in group B was 63.8% (482 of 755 embryos), and among the 482 embryos 465 embryos (96.5%) which progressed to the two- to eight-cell stage. After thawing, the embryo numbers were 106 (22.8%), 94 (20.2%), 89 (19.1%), and 112 (24.1%) of grades 1, 2, 3, and above 4, respectively. There was no difference in embryo quality change after the freezing-thawing procedure between the groups. Implantation rates (31.1% vs. 34.3%) were not significant. However hCG positive rates in group A (40%) were higher than group B, but not statistically significant. Clinical pregnancy rate (26% vs. 25.9%), on going pregnancy rates (>20 weeks) were not significant (26% vs. 25%). Conclusion: We compared embryo quality change, survival rates, and pregnancy rates between high infusion frequency group and low infusion frequency group and the results were similar between the two groups. Therefore, high infusion frequency of liquid nitrogen for cryopreservation is a worthy method to preserve in human embryos.

• Clinical and Experimental Reproductive Medicine
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• 제21권1호
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• pp.69-76
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• 1994

The survival and pregnancy rates were compared between non-frozen embryos and cryopreserved embryos at either pronucleate or 2-4 cell stages using the freezing and thawing techniques being identical in both groups were compared with fresh embryos. 496 embryos were frozen with 1, 2-propanediol and sucrose and 117 2-4 cell stages embryos had been thawed and 79.6 and 66.0% of them respectively were survival. Clinical pregnancy rate was 19.2% for embryos frozen at the pronucleate stage and 19.0% for embryos frozen at the 2-4 cell stages while the pregnancy rate of non-frozen embryos was 21.3%. There were no significant difference in the survival and pregnancy rates of embryos frozen at pronucleate and 2-4 cell stages. The current cumulative pregnancy rate per retrieval in all cycles with frozen zygotes is 35.4 %, consid~ erably higher than observed in single transfers of embryos without cryopreservation(21.3%); predicted pregnancy rate after transfer of all frozen embryos is 43.3 %. It is concluded that firstly, the survival and pregnancy rate of cryopreserved embryos at pronucleate or 2-4 cell stages are very similar to those from their fresh embryos and non-frozen embryos and secondly, cryopreservation substantially enhances pregnancy attainment from in vitro fertilization.

• 한국수정란이식학회지
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• 제27권1호
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• pp.63-69
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• 2012

The objective of this study was to investigate the effectiveness of cryopreservation methods for the effect of various vitrification containers, such as EM-grid, OPS, or cryo-loop on the survival and developmental rate of vitrified mouse pronuclear embryos, and mouse cleavage embryo, at 21, 24, 27 and 30 hr after hCG injection. Post-thaw cleavage was similar among treatments, while the developmental rates of mouse blastocyst and hatched blastocyst were higher ($p$ <0.05) in 27 hr and 30 hr than 21 hr. The developmental rate of hatched blastocyst at vitrified cleavage mouse embryos in cryo-loop was significantly higher than vitrified pronuclear embryos of control group as well as EM-grid and OPS ($p$ <0.05). The developmental rate using cryo-loop was higher than EM-grid, but in case of OPS at vitrified cleavage and mouse pronuclear embryos, no significant difference was noticed. These results of our study show that the developmental rates of mouse embryos were unaffected by various vitrification containers, but in case of mouse embryos and hatched blastocysts at late vitrified pronuclear embryos the developmental rates were higher than early vitrified pronuclear embryos. Moreover, the developmental rate of hatched blastocyst at vitrified cleavage mouse embryos was significantly higher than vitrified pronuclear embryos. For better execution of this study, it will be mandatory to include improvement of vitrification containers, cryopreservation methods and conditions, higher survival rate, safe preservation, contamination and embryo loss.

• Clinical and Experimental Reproductive Medicine
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• 제20권1호
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• pp.31-36
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• 1993

The effects of freezing and 1,2-propanediol on early and late pronucleate stage mouse ova were investigated in terms of survival after thawing and development in vitro. The samples were divided into two groups according to different age in pronucleate ova: ova in(1) early pronuclear stage with two distant pronuclei at 18h after hCG injection, and (2) late pronuclear stage with adjacent pronuclei at 30h. Zygotes in the late pronuclear stage have been proven to be more resistant to 1,2-propanediol, showing a significantly higher developmental rate than zygotes in early stage (80.3 versus 66.3%, <0.05), but survival rate was similar in the two groups (91.0 versus 93.5%). After freezing and thawing, survival and developmental rates were decreased in both groups when compared to the control group (54.3 versus 92.3%, 47.7 versus 73.3%. respectively). And developmental rate in the late pronuclear stage zygotes showed significantly higher than in early (55.4 versus 40.0%) after thawing. In conclusion, early pronucleate mouse ova have a lower developmental capacity in vitro and a lower survival rate after freezing and thawing than late ova. These findings suggest that the timing of freezing could be important for survival and further development in vitro in cryopreservation of human pronucleate ova.

• Clinical and Experimental Reproductive Medicine
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• 제37권4호
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• pp.293-305
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• 2010

난소과자극증후군은 발생 시 생명을 위협하는 심각한 의인성 합병증으로, 불임 치료를 목적으로 성선자극호르몬을 사용하여 과배란을 유도할 때 발생한다. 따라서, 과배란 유도를 하기에 앞서 위험요인을 가진 환자를 파악하여 저용량의 성선자극호르몬을 사용하거나, GnRH antagonist protocol을 이용함으로써 발생을 예방하는 것이 중요하고, 과배란 유도 중 ovarian hyperstimulation syndrome (OHSS)의 발생이 예측될 때는 성선자극호르몬 투여 시 coasting을 하고 난포 성숙을 유도할 때 저용량의 hCG 혹은 GnRH agonist를 이용하고, 중증의 OHSS가 예측될 때에는 주기취소로 OHSS의 유병기간을 줄이거나 배아동결 등을 통해 후발성 난소과자극증후군을 예방할 수 있다. 그리고, metformin과 dopamine agonist를 난소과자극증후군을 예방을 위해 고려해 볼 수 있겠다.

• 한국수정란이식학회지
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• 제18권3호
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• pp.179-186
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• 2003

Human embryonic stem (hES) cell lines have been derived from human blastocysts and are expected to have far-reaching applications in regenerative medicine. The objective of this study is to improve freezing method with less cryo-injuries and best survival rates in hES cells by comparing various vitrification conditions. For the vitrifications, ES cells are exposed to the 4 different cryoprotectants, ethylene glycol (EG), 1,2-propanediol (PROH), EG with dime-thylsulfoxide (DMSO) and EG with PROH. We compared to types of vehicles, such as open pulled straw (OPS) or electron microscopic cooper grids (EM grids). Thawed hES cells were dipped into sequentially holding media with 0.2 M sucrose for 1 min, 0.1 M sucrose for 5 min and holding media for 5 min twice and plated onto a fresh feeder layer. Survival rates of vitrified hES cells were assessed by counting of undifferentiated colonies. It shows high survival rates of hES cells frozen with EG and DMSO (60.8％), or EG and PROH(65.8％) on EM grids better than those of OPS, compared to those frozen with EG alone (2.4％) or PROH alone (0％) alone. The hES cells vitrified with EM grid showed relatively constant colony forming efficiency and survival rates, compared to those of unverified hES cells. The vitrified hES cells retained the normal morphology, alkaline phosphates activity, and the expression of SSEA-3 and 4. Through RT-PCR analysis showed Oct-4 gene expression was down-regulated and embryonic germ layer markers were up-regulated in the vitrified hES cells during spontaneous differentiation. These results show that vitrification method by using EM grid supplemented with EG and PROH in hES cells may be most efficient at present to minimize cyto-toxicity and cellular damage derived by ice crystal formation and furthermore may be employed for clinical application.