The impact of post-warming culture duration on clinical outcomes of vitrified-warmed single blastocyst transfer cycles / 대한생식의학회지

Objective@#The objective of the study was to compare the effects of long-term and short-term embryo culture to assess whether there is a correlation between culture duration and clinical outcomes. @*Methods@#Embryos were divided into two study groups depending on whether their post-warming culture period was long-term (20–24 hours) or short-term (2–4 hours). Embryo morphology was analyzed with a time-lapse monitoring device to estimate the appropriate timing and parameters for evaluating embryos with high implantation potency in both groups. Propensity score matching was performed to adjust the confounding factors across groups. The grades of embryos and blastoceles, morphokinetic parameters, implantation rate, and ongoing pregnancy rate were compared. @*Results@#No significant differences were observed in the implantation rate or ongoing pregnancy rate between the two groups (56.3% vs. 67.9%, p=0.182; 47.3% vs. 53.6%, p=0.513). After warming, there were more expanded and hatching/hatched blastocysts in the long-term culture group than in the short-term culture group, but there was no significant between-group difference in embryo grade. Regarding pregnancy outcomes, the completion of re-expansion was faster in women who became pregnant than in those who did not for both culture durations (long-term: 2.19±0.63 vs. 4.11±0.81 hours, p=0.003; short-term: 1.17±0.29 vs. 1.94±0.76 hours, p=0.018, respectively). @*Conclusion@#The outcomes of short-term culture and long-term culture were not significantly different in vitrified-warmed blastocyst transfer. Regardless of the post-warming culture time, the degree of blastocyst re-expansion 3–4 hours after warming is an important marker for embryo selection.

Effect of a dual trigger on oocyte maturation in young women with decreased ovarian reserve for the purpose of elective oocyte cryopreservation / 대한생식의학회지

Objective@#The aim of this study was to determine whether co-administration of a gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG) for final oocyte maturation improved mature oocyte cryopreservation outcomes in young women with decreased ovarian reserve (DOR) compared with hCG alone. @*Methods@#Between January 2016 and August 2019, controlled ovarian stimulation (COS) cycles in women (aged ≤35 years, anti-Müllerian hormone [AMH] <1.2 ng/mL) who underwent elective oocyte cryopreservation for fertility preservation were retrospectively analyzed. @*Results@#A total of 76 COS cycles were triggered with a GnRH agonist and hCG (the dual group) or hCG alone (the hCG group). The mean age and serum AMH levels were comparable between the two groups. The duration of stimulation, total dose of follicle-stimulating hormone used, and total number of oocytes retrieved were similar. However, the number of mature oocytes retrieved and the oocyte maturation rate were significantly higher in the dual group than in the hCG group (p=0.010, p<0.001). After controlling for confounders, the dual-trigger method remained a significant factor related to the number of mature oocytes retrieved (p=0.016). @*Conclusion@#We showed improved mature oocyte collection and maturation rate with the dual triggering of oocyte maturation in young women with DOR. A dual trigger appears to be more beneficial than hCG alone in terms of mature oocyte cryopreservation for young women with DOR.

The impact of post-warming culture duration on clinical outcomes of vitrified-warmed single blastocyst transfer cycles / 대한생식의학회지

Objective@#The objective of the study was to compare the effects of long-term and short-term embryo culture to assess whether there is a correlation between culture duration and clinical outcomes. @*Methods@#Embryos were divided into two study groups depending on whether their post-warming culture period was long-term (20–24 hours) or short-term (2–4 hours). Embryo morphology was analyzed with a time-lapse monitoring device to estimate the appropriate timing and parameters for evaluating embryos with high implantation potency in both groups. Propensity score matching was performed to adjust the confounding factors across groups. The grades of embryos and blastoceles, morphokinetic parameters, implantation rate, and ongoing pregnancy rate were compared. @*Results@#No significant differences were observed in the implantation rate or ongoing pregnancy rate between the two groups (56.3% vs. 67.9%, p=0.182; 47.3% vs. 53.6%, p=0.513). After warming, there were more expanded and hatching/hatched blastocysts in the long-term culture group than in the short-term culture group, but there was no significant between-group difference in embryo grade. Regarding pregnancy outcomes, the completion of re-expansion was faster in women who became pregnant than in those who did not for both culture durations (long-term: 2.19±0.63 vs. 4.11±0.81 hours, p=0.003; short-term: 1.17±0.29 vs. 1.94±0.76 hours, p=0.018, respectively). @*Conclusion@#The outcomes of short-term culture and long-term culture were not significantly different in vitrified-warmed blastocyst transfer. Regardless of the post-warming culture time, the degree of blastocyst re-expansion 3–4 hours after warming is an important marker for embryo selection.

Effect of a dual trigger on oocyte maturation in young women with decreased ovarian reserve for the purpose of elective oocyte cryopreservation / 대한생식의학회지

Objective@#The aim of this study was to determine whether co-administration of a gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG) for final oocyte maturation improved mature oocyte cryopreservation outcomes in young women with decreased ovarian reserve (DOR) compared with hCG alone. @*Methods@#Between January 2016 and August 2019, controlled ovarian stimulation (COS) cycles in women (aged ≤35 years, anti-Müllerian hormone [AMH] <1.2 ng/mL) who underwent elective oocyte cryopreservation for fertility preservation were retrospectively analyzed. @*Results@#A total of 76 COS cycles were triggered with a GnRH agonist and hCG (the dual group) or hCG alone (the hCG group). The mean age and serum AMH levels were comparable between the two groups. The duration of stimulation, total dose of follicle-stimulating hormone used, and total number of oocytes retrieved were similar. However, the number of mature oocytes retrieved and the oocyte maturation rate were significantly higher in the dual group than in the hCG group (p=0.010, p<0.001). After controlling for confounders, the dual-trigger method remained a significant factor related to the number of mature oocytes retrieved (p=0.016). @*Conclusion@#We showed improved mature oocyte collection and maturation rate with the dual triggering of oocyte maturation in young women with DOR. A dual trigger appears to be more beneficial than hCG alone in terms of mature oocyte cryopreservation for young women with DOR.

Clinical outcomes of single versus double blastocyst transfer in fresh and vitrified-warmed cycles / 대한생식의학회지

OBJECTIVE: Assisted reproductive technology has been associated with an increase in multiple pregnancies. The most effective strategy for reducing multiple pregnancies is single embryo transfer. Beginning in October 2015, the National Supporting Program for Infertility in South Korea has limited the number of embryos that can be transferred per in vitro fertilization (IVF) cycle depending on the patient's age. However, little is known regarding the effect of age and number of transferred embryos on the clinical outcomes of Korean patients. Thus, this study was performed to evaluate the effect of the number of transferred blastocysts on clinical outcomes. METHODS: This study was carried out in the Fertility Center of CHA Gangnam Medical Center from January 2013 to December 2014. The clinical outcomes of 514 women who underwent the transfer of one or two blastocysts on day 5 after IVF and of 721 women who underwent the transfer of one or two vitrified-warmed blastocysts were analyzed retrospectively. RESULTS: For both fresh and vitrified-warmed cycles, the clinical pregnancy rate and live birth or ongoing pregnancy rate were not significantly different between patients who underwent elective single blastocyst transfer (eSBT) and patients who underwent double blastocyst transfer (DBT), regardless of age. However, the multiple pregnancy rate was significantly lower in the eSBT group than in the DBT group. CONCLUSION: The clinical outcomes of eSBT and DBT were equivalent, but eSBT had a lower risk of multiple pregnancy and is, therefore, the best option.

Effect on Survival and Developmental Competence of Vitrified Mouse Embryos Using Various Cryoprotectants and Cooling Speeds / 대한불임학회지

OBJECTIVE: Vitrification requires a high concentration of cyroprotectant (CPA) and an elevated cooling speed to avoid ice crystal formation. We have evaluated the effect of different combinations of cooling rate and CPA on embryonic integrity (developmental competence) in order to increase the efficiency of vitrification without impairing embryo viability. We hypothesized that the combination of CPA or the increase of cooling rates can reduce the concentration of toxic CPA for vitrification. As consequently, we performed experiments to evaluate the effect of various composition of CPA or slush nitrogen (SN2) on the mouse embryonic development following vitrification using low CPA concentration. METHODS: Vitrification of mouse embryos was performed with EM grid using liquid nitrogen (LN2) or SN2 and different composition of CPAs, ethylene glycol (EG) and dimethylsulfoxide (DMSO). After vitrification-warming process, their survival and blastocyst formation rates were examined. For analyzing long-term effect, these blastocysts were transferred into the uterus of foster mothers. RESULTS: Survival and blastocyst formation rates of vitrified embryos were higher in EG+DMSO group than those in EG only. Furthermore, the group using SN2 with a lower CPA concentration showed a higher survival of embryos and developmental rates than group using LN2. CONCLUSION: The combination of EG and DMSO as CPAs may enhance the survival of mouse embryos and further embryonic development after vitrification. SN2 can generate high survival and developmental rate of vitrified/warmed mouse embryos when a lower concentration of CPA was applied. Therefore, these systems may contribute in the improvement of cryopreservation for fertility preservation.

Hebei Spirit oil spill exposure and acute neuropsychiatric effects on residents participating in clean-up work / 한국역학회지

OBJECTIVES: Hebei Spirit oil spill accident has brought about the worst coastal oil contamination in Korean history. Following the accident, residents and volunteers, number exceeding a million from nationwide, were exposed to chemicals from the crude oil itself and dispersants, including volatility organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals through the clean-up works over months. This study was undertaken to investigate the effect of clean-up work on the peripheral nerve function and psychologic status of the residents after a prolonged exposure to clean-up work after the oil spill exposure. METHODS: We performed a study on the residents of Jango-do Island, Chungnam, on 5 and 12 January 2008, six to eight weeks after the accident. A questionnaire on general characteristics, Korean Beck Depression Inventory (K-BDI), color vision test (Lanthony desaturated D-15 test), and vibration perception threshold test were done. Among 210 residents with 30 years or older, 63 (30%) finished questionnaires and completed at least one among K-BDI, color vision test, or vibration perception threshold test. Descriptive statistics was done on the residents. RESULTS: The residents participated in clean-up work for average 20 days, max 30 days, during 6 weeks following the accident. Average work hours were 7.4 hours per day, max 10 hours. On K-BDI, 21 (33.3%) had a severe depressive state. Mean color confusion index was 1.29 in the right and 1.20 in the left. Mean vibration perception threshold was 3.69 VU (right) and 3.55 VU (left), respectively. DISCUSSIONS AND CONCLUSIONS: Compared to literature report, the residents had higher depression scale. Color vision threshold was not higher compared to general population near an industrial complex. Vibration perception threshold was significantly higher than the residents of similar age living near an abandoned mine in southern coastal area only in the age group of forties. These suggests there is some evidence of neuropsychiatric effect related to oil cleaning work and a mid- and long-term study of the oil exposure health effects with continuous monitoring should be done for the exposed residents in the affected area.