• Clinical and Experimental Reproductive Medicine
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• 제38권3호
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• pp.148-152
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• 2011

Objective: Laser-assisted intracytoplasmic sperm injection (LA-ICSI), also known as micro-opening or thinning of the zona pellucida (ZP) prior to ICSI, may help to reduce mechanical damage to the oocyte during the procedure. The aim of the present study was to evaluate and analyze the efficacy of our institutional LA-ICSI program, which features laser-assisted ZP thinning prior to ICSI, in comparison with conventional ICSI (C-ICSI), performed on patients with different clinical characteristics. Methods: Patients undergoing a total of 212 ICSI cycles were randomly divided into an LA-ICSI group (106 cycles) and a conventional ICSI group (106 cycles). To reduce tissue damage, we thinned the ZP by approximately 70%, using a laser, before ICSI. Patients thus treated formed the LAICSI group. Comparisons included the morphological quality of transferred embryos, blastocyst development of the remaining embryos, and clinical pregnancy, in terms of ICSI method and patient characteristics. Results: Fertilization, development of remaining embryos, and pregnancy rate were significantly higher in the LA-ICSI group compared with the C-ICSI group. Fertilization, embryonic development, and the pregnancy rate were all improved in younger patients (<38 years of age) and in those who underwent a low number of IVF-ET attempts (<3 trials). In addition, the pregnancy rate was increased in older patients. Conclusion: LA-ICSI may be useful in improving the chance of pregnancy in all ICSI patients.

• Clinical and Experimental Reproductive Medicine
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• 제46권1호
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• pp.36-40
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• 2019

A viable spermatozoon is a prerequisite for fertilization in intracytoplasmic sperm injection (ICSI). Thus, it is crucial to select viable but immotile spermatozoa on the day of ICSI. We report conflicting results in the identification of viable but immotile spermatozoa between the eosin-nigrosin staining and the laser test, which resulted in confusion for embryologists during assisted reproductive technology (ART). Three patients' semen samples that showed no motile spermatozoa are described in this report. To identify viable spermatozoa, we used both the eosin-nigrosin test and the laser test for each sample, and repeated the semen analysis twice in each patient. Viable but immotile spermatozoa selected by the laser test were used for ICSI. Viable spermatozoa were detected by both the eosin-nigrosin and laser tests in two patients (case 1, 95.00% vs. 24.21% and 92.68% vs. 22.22%; case 2, 41.18% vs. 23.48% and 39.81% vs. 22.52%), indicating consistent results between the two methods. In the third patient, the eosin-nigrosin test yielded viability rates of 20.75% and 19.14%, while the result of the laser test was 0%. Thus, testicular aspiration was performed to collect viable sperm from this patient. Normal fertilization was achieved after the injection of viable but immotile spermatozoa selected from these patients by the laser test, resulting in the birth of two healthy babies. Our study documents a case where the eosin-nigrosin test showed a limitation in identifying viable but immotile spermatozoa for ART, while the laser test may overcome this limitation. Larger samples may be required to corroborate the clinical value of the laser test.

• 한국가축번식학회지
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• 제24권2호
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• pp.143-154
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• 2000

본 연구는 생식보조기법을 시행한 불임환자로부터 얻은 난자를 일반적인 수정법과 세포질내 정자직접주입법으로 수정을 유도한 다음 정상수정에 실패한 난자에 대한 미세소관과 염색체의 형태학적 차이를 laser scanning confocal microscope를 이용하여 비교분석하고자 실시하였다. 일반적 수정법 혹은 세포질내 정자직접주입법 실시 후 18시간째에 해부현미경 하에서 난자를 관찰하였을 때 전핵형성에 실패한 미수정란, 한 개의 전핵 또는 3개이상의 전핵의 형성이 관찰된 이상수정란으로 구분하여 연구를 실시하였다. 미세소관의 관찰을 위해서 (-tubulin antibody를 반응시킨 후 형광물질이 부착된 2차항체와 반응시킨 후 관찰하였으며 염색체의 관찰을 위해서는 propidium iodide로 염색한 다음 confocal microscope 하에서 관찰하였다. 연구결과 대부분의 난자는 수정과정중에 있었으나 일부의 난자에서는 특정단계에서 정지되어 있는 것이 관찰되었다. 즉, 감수분열 중기에서 정자의 침입이 이루어지지 않은 경우, 정자의 침입은 이루어졌으나 sperm aster 형성이 불완전한 경우, 웅성 및 자성전핵의 형성에 실패한 경우 및 전핵의 위치가 불완전한 경우 등이 관찰되었고 이들 난자의 경우 높은 비율로 미세소관과 염색체의 이상이 관찰되었다. 이상의 연구결과로 미루어 볼 때 생식보조기법의 시술과정에서 채취되는 난자의 수정실패의 원인은 세포골격기관 특히 미세소관의 이상과 염색체의 이상에 기인되는 것으로 사료되면 이러한 세포골격 구성물질의 이상에 대해서는 추후에 세포조직학적 또는 분자생물학적 분석이 필요하다고 하겠다.

• Clinical and Experimental Reproductive Medicine
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• 제45권3호
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• pp.129-134
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• 2018

Objective: In frozen and thawed embryos, the zona pellucida (ZP) can be damaged due to hardening. Laser-assisted hatching (LAH) of embryos can increase the pregnancy rate. This study compared thinning and drilling of the ZP before frozen embryo transfer (FET). Methods: Patients were randomly allocated into two groups for LAH using thinning or drilling on day 2 after thawing. Twenty-five percent of the ZP circumference and 50% of the ZP thickness was removed in the thinning group, and a hole $40{\mu}m$ in diameter was made in the drilling group. Results: A total of 171 in vitro fertilization/intracytoplasmic sperm injection FET cycles, including 85 cycles with drilling LAH and 86 cycles with thinning LAH, were carried out. The thinning group had a similar ${\beta}$-human chorionic gonadotropin-positive rate (38.4% vs. 29.4%), implantation rate (16.5% vs. 14.4%), clinical pregnancy rate (36.0% vs. 25.9%), miscarriage rate (5.8% vs. 2.4%), ongoing pregnancy rate (30.2% vs. 23.5%), and multiple pregnancy rate (7.0% vs. 10.6%) to the drilling LAH group. There were no significant differences in pregnancy outcomes between subgroups defined based on age (older or younger than 35 years) or ZP thickness (greater or less than $17{\mu}m$) according to the LAH method. Conclusion: The present study demonstrated that partial ZP thinning or drilling resulted in similar outcomes in implantation and pregnancy rates using thawed embryos, irrespective of women's age or ZP thickness.