• Clinical and Experimental Reproductive Medicine
• /
• 제22권2호
• /
• pp.183-189
• /
• 1995

In human IVF-ET, the development and morphology of the embryo have been known to affect implantation and pregnancy rates(PRs). Recently, pregnancy has been reported to related to the embryos with thick zona-pellucida, high levels of fragmentation, poor blastomere development and zona hardening. Although the mechanism of implantation is unclear, it is thought that the hatching process precedes implantation and that the hatching is related to implantation and PRs. This study was carried out to investigate the effect of assisted hatching(AHA) on the improvement of PRs in human IVF-ET. The results were as follows; 1. The PRs of the AHA group (40.8%) was significantly higher than that of control group(27.2%)(P<0.01). 2. According to the age of patients, the PRs of control and AHA groups were 33.9%(20/59), 44,4%(12/27) in <30 yrs, 26.1%(30/115), 38.3%(18/47) in 31-35 yrs, 22.4%(13/58), 41.4%(12/29) in >36 yrs, respectively. 3. According to the factors of infertility in AHA group, unexplained(immunologic factor) (40.0%) and male factors(41.9%) were higher than female(tubal obstruction, endometriosis, adhesion) factor (28.9%). As a result, it is suggested that AHA technique improve the PRs in poor prognosis patients. It is concluded that AHA method can be used to improve the PRs in human lVF-ET.

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

• 한국가축번식학회지
• /
• 제14권1호
• /
• pp.36-42
• /
• 1990

The effect of preincubation on in vitro maturation and fertility were investigated using preovulatory oocytes with and without cumulus cells obtained from superovulated ouot-bred ICR mice. Oocytes were recovered from fully grown folicle at 10 hr after hCG administration. A part of oocytes recovered were treated with the solution of 0.1% hyaluronidase to remove cumulus cells. Both intact and treated oocytes were then incubated for 0 to 6hr in mT6 medium containing 0.3% BSA. After incubation for various times, a part of oocytes were subjected to the investigation of nuclear maturation and the remaining oocytes were used fro the induction of in vitro fertilization by adding them into medium containing capacitated mice epididymal spermatozoa. Above all, the percentage of preovulatory oocytes at the stage of metaphase II after preincubation for 0, 2, 4 and 6hr was 15.8, 36.4, 47.5 and 66.7%, respectively, suggesting the in vitro maturation of oocytes during their incubation. On the other hand, fertilizatin rate of oocytes preincubated for 0, 2, 4 and 6hr with and without cumulus cells were 41.0, 58.7, 68.7 and 75.6%, and 50.0, 45.1, 37.8 and 39.2%, respectively. No significant differences in fertilization rate between preovulatory oocytes preincubated for 6hr with cumulus cells and naturally ovulated were observed. These results suggest that cumulus cells take very important role in maturtion of oocytes in vitro. The precentage of preovulatory oocytes developed to 2-cell stage in vitro fertilization following preincubation for 0 to 6hr with and without cumulus cells ranged from 48.5 to 82.4% and 36.9 to 56.1%, respectively. Also, the rates of oocytes developed to blastocyst in vitro fertilization after preincubation for 0 to 6hr with and without cumulus cells were 28.1, 39.3, 42.5 and 44.0% and 12.5, 32.6, 24.4 and 15.5%, respectively. From these results, it could be said that fertility of preovulatory oocytes with cumulus cells could be improved to the level of that of naturally ovulated oocytes by adquate preincubation in vitro. Cumulus cells may, therefore, affect in vitro maturation, fertilization and following development of oocytes by influencing zona hardening.