• Journal of Embryo Transfer
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• v.26 no.1
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• pp.85-89
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• 2011

Somatic cell nuclear transfer (SCNT) is a useful tool for reproducing genetically identical animals or producing transgenic animals. Many reports have demonstrated that the efficiency of animal cloning by SCNT requires reprogramming of the somatic nucleus to a totipotent like-state. The SCNT-related reprogramming might mimic the natural reprogramming process that occurs during normal mammalian development. However, recent evidence indicates that the reprogramming event by SCNT is incomplete. In this study, the traditional SCNT procedure (TNT) was modified by injecting donor nuclei into recipient cytoplasm prior to the enucleation process to expose the donor nucleus before removing the karyoplast containing the chromosomes of the oocytes which might possess additional reprogramming factors, and this modified technique was named as reversing the usual order of SCNT (RONT). Other procedures including activation and in vitro culture were the same as TNT. Contrary to expectations, the rate of blastocyst development was not different significantly between RONT and TNT (8.6% and 7.9%, respectively). However, duration of micromanipulation performed by the same technician and equipments was remarkably reduced because the ruptured oocytes after nuclear injection were excluded from the enucleation process. This study suggests that RONT, a simplified SCNT protocol, shortens the duration of SCNT procedure and this less time-costing protocol may enable the researchers to perform murine SCNT easier.

• 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.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.3
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• pp.261-265
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• 2000

Objective: This study was performed to evaluate the influence of maternal age on embryo quality and the frequency of multiple pregnancy in IVF-ET program. Method: 86 conventional IVF-ET cycles were divided into three groups according to the age by 5 year (group A: 26-30, group B: 31-35, group C: 36-40 yrs). The in vitro fertilization and development outcome (fertilization, cleavage and high quality embryo rate) and the pregnancy outcome (pregnancy, implantation, G-sac/high quality embryo and multiple pregnancy rate) were examined. And then, these results were compared among the groups. Results: The rates of fertilization (62.7, 68.5 and 65.4%, respectively) and cleavage (95.6, 97.6 and 98.0%, respectively) were not different among the groups. And the high quality embryo (HQE) rate also was not different among the groups (61.8, 62.9 and 62.8%, respectively). The pregnancy rate of group C (23.3%) was significantly lower than that of group A (41.2%) and B (48.7%). And the implantation rate was significantly decreased with advance in maternal age (group A; 17.3%, B; 12.6% and C; 6.0%). The G-sac/high quality embryo rate was significantly higher in group A (70.8%) when compared to group B (32.2%) and C (40.0%). On the other hand, the multiple pregnancy rate was significantly lower in group C (14.3%) when compared to group A (71.4%) and B (36.8%). Conclusion: The pregnancy rate was significantly decreased over 35 years. The G-sac/HQE and multiple pregnancy rate were significantly high below 31 years. Thus, these results suggest that the number of high quality embryo transferred should be limited by the age and another criteria for embryo quality evaluation were required for single embryo transfer.

• Journal of Embryo Transfer
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• v.6 no.2
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• pp.1-17
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• 1991

It is widely recognized that the embryonic or fetal loss after breeding is common in the cattle and that it is an important factor affecting reproductive efficiency. The causes of this loss have been subject of extensive researches and the results indicate that the embryonic mortality may he primary factor responsible for low pregnancy rates in non-embryo transfer bovine populations as well as embryo transfer programs. However, it's causes are still not clearly understood. The embryonic mortality or pregnancy rate has been influenced by various embryonic and maternal effects related to genetic and environmental factors. The timing and extent of embryonic mortality vanes greatly according to authors and estimating methods, because it is difficult to make direct measurements. The major important factors that may influence the embryonic losses or pregnancy rates after embryo transfer can be summeirized. 1.When an embryo is transferred to unmated recipients, the contralateral transfer to corpus luteum results in a lower survival rate than ipsilateral deposition. When the embryos are transferred for the production of twin calves, their survivals and twin pregnancies have quite inconsistent according to the transfer methods either to the unmated-synchronized or already mated recipients and more works are needed to accurrately clarify the previous results. 2.Although embryos can be cultured in vitro some hours without the great declines in pregnancy rates, the rates differ markedly among culture times and media but may be improved by co-transfer systems. 3.Embryo developmental stages and quality grades clearly affect the survival rate following freezing and the pregnancy rate after transfer and the selection of embryos without chromosome abnormalities and of high fertile semen may also be considered to increase the pregnancy rates. 4.Many researches have attempted to relate the plasma progesterone levels to pregnancy rates and others have done either direct progesterone supplementation or luteal stimulation by hCG treatment in order to increase the pregnancy rates. However, these effects on pregnancy rates are inconsistent and also contradictory. 5.The asynchrony between donors or embryos and recipients may he a major cause of embryo death and low pregnancy rate and the sensitivity to uterine asynchyony differs in according to the quality and stages of embryos. 6.The extremes of poor or over nutrition during early pregnancy in the recipients are detrimental to the survival of embryos and the good body condition is required to prevent a reduejion of pregnancy rates. The uterine pathogens in embryonic mortality or fertility have been questioned but the infection of C.pyogenes and Campylobacter fetus is still important pathogens. 7.The heat stress during early pregnancy may reduce conceptus weight and possibly increase the embryonic mortality.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.223-229
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• 2007

The fetus is completely dependent on mother for glucose and other nutrient transfer across the placenta. At birth, when the maternal supply is discontinued, the neonate must adjust to an independent existence. The changes in the neonate's glucose homeostasis during this transition to the extrauterine environment are influenced by the mother's metabolism and intrinsic fetal and placental problems. Maturation of carbohydrate homeostasis results from a balance between substrate availability and coordination of developing hormonal, enzymatic, and neural systems. These mechanisms may not be fully developed in neonates, so the neonate is vulnerable to carbohydrate disequilibrium resulting in damage to the central nervous system. Hypoglycemia is a relatively common metabolic problem seen during newborn care. However its definition, management and long term sequalae remain controversial. Hyporglycemia occurs frequently as a transient disorder with excellent prognosis. It also may persist and recur and cause permanent neurological complications. Although the key to effective treatment of hypoglycemia is diagnostic specific, the maintenance of euglycemia is critical to the preservation of central nervous system function. This article discusses physiology of perinatal glucose homeostasis, focusing on evaluation and treatment of hypoglycemia.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.2
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• pp.111-117
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• 2017

Objective: The aim of this study was to evaluate pregnancy outcomes and the live birth rate at 1-year age increments in women aged ${\geq}40years$ undergoing fresh non-donor in vitro fertilization (IVF) and embryo transfer (ET), and to identify predictors of success in these patients. Methods: This retrospective study was performed among women ${\geq}40years$ of age between 2004 and 2011. Of the 2,362 cycles that were conducted, ET was performed in 1,532 (73.1%). Results: The clinical pregnancy rate and live birth rate in women ${\geq}40years$ significantly decreased with each year of increased age (p<0.001). Maternal age (odds ratio [OR], 0.644; 95% confidence interval [CI], 0.540-0.769; p<0.001), basal follicle-stimulating hormone (FSH) levels (OR, 0.950; 95% CI, 0.903-0.999; p=0.047), the number of high-quality embryos (OR, 1.258; 95% CI, 1.005-1.575; p=0.045), and the number of transferred embryos (OR, 1.291; 95% CI, 1.064-1.566; p=0.009) were significant predictors of live birth. A statistically significant increase in live birth rates was seen when ${\geq}3$ embryos were transferred in patients 40 to 41 years of age, whereas poor pregnancy outcomes were seen in patients ${\geq}43years$ of age, regardless of the number of transferred embryos. Moreover, the cumulative live birth rate increased in patients 40 to 42 years of age with repeated IVF cycles, but the follicle-stimulating hormone in those ${\geq}43years$ of age rarely showed an increase. Conclusion: IVF-ET has acceptable outcomes in those < 43 years of age when a patient's own oocytes are used. Maternal age, basal FSH levels, and the number of high-quality embryos and transferred embryos are useful predictors of live birth.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.930-934
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• 2013

The growth performance of embryo-transferred Japanese Black calves that were born from, and suckled by, Japanese Shorthorn cows in a cow-calf grazing system (BS-group, n = 5) was compared to that of Japanese Black calves from Japanese Black cows in a cowshed (BB-group, n = 5). The daily weight gain from birth to 1 month was higher in the BS-group than in the BB-group (p<0.01), and the same trend (p<0.05) was observed at 2 and 3 months of age. This resulted in body weight that was significantly higher for the BS-group between 1 and 3 months of age than what was observed for the BB-group (p<0.05). Heart girth was significantly greater in the BS-group than in the BB-group throughout the experimental period (p<0.01), and chest depth and withers height in the BS-group were significantly greater from 2 to 4 months of age (p<0.05) and at 4 months of age only (p<0.05). No difference in body length (p>0.05) was observed between the groups. These results suggest that the maternal effect of Japanese Shorthorn cows was positive for embryo-transferred Japanese Black calf growth during the early suckling stage. As Japanese Black calves are traded at a high price on the Japanese market, we conclude that this proposed production system is likely to improve the profitability of herd management in upland Japan.

• Journal of Nutrition and Health
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• v.18 no.3
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• pp.209-216
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• 1985

The plasma levels of 23 free amino acids in both the umbilical circulation (umbilical vein and artery) and the maternal circulation (antecubital vein, uterine vein and iliac artery ) of 34 pregnant women were measured at delivery by the cesarean section. Each amino acid with the exception of glutamate was found to be in higher concentration in the fetal blood and the cord plasma characterized by hyperaminoacidemia with a marked increase of the lysine and ornithine levels. The linear relationships found between the amino acids concentrations of iliac artery and those of umbilical vein suggest three transport groups across the placental membrane One group consists of neutral amino acids whose slopes are equal to one and the other two groups are characterized by their slopes higher and lower than unity respectivly. This division into three groups is tentatively explained by the result of a dynamic equilibrium between active transport towards the fetus and diffusion back towards the maternal circulation.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.1
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• pp.75-84
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• 2024

Objective: The purpose of this study was to evaluate the impact of preimplantation genetic testing for aneuploidy (PGT-A) on clinical outcomes among high-risk patients. Methods: This retrospective study involved 1,368 patients and the same number of cycles, including 520 cycles with PGT-A and 848 cycles without PGT-A. The study participants comprised women of advanced maternal age (AMA) and those affected by recurrent implantation failure (RIF), recurrent pregnancy loss (RPL), or severe male factor infertility (SMF). Results: PGT-A was associated with significant improvements in the implantation rate (IR) and the ongoing pregnancy rate/live birth rate (OPR/LBR) per embryo transfer cycle in the AMA (39.3% vs. 16.2% [p<0.001] and 42.0% vs. 21.8% [p<0.001], respectively), RIF (41.7% vs. 22.0% [p<0.001] and 47.0% vs. 28.6% [p<0.001], respectively), and RPL (45.6% vs. 19.5% [p<0.001] and 49.1% vs. 24.2% [p<0.001], respectively) groups, as well as the IR in the SMF group (43.3% vs. 26.5%, p=0.011). Additionally, PGT-A was associated with lower overall incidence rates of early pregnancy loss in the AMA (16.7% vs. 34.3%, p=0.001) and RPL (16.7% vs. 50.0%, p<0.001) groups. However, the OPR/LBR per total cycle across all PGT-A groups did not significantly exceed that for the non-PGT-A groups. Conclusion: PGT-A demonstrated beneficial effects in high-risk patients. However, our findings indicate that these benefits are more pronounced in carefully selected candidates than in the entire high-risk patient population.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.234-238
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• 1999

Purpose : This study was performed to evaluate the seropositivities and levels of Hepatitis A Virus(Hav) antibody in term pregnant women and their neonates, and the transplacental transfer rate of maternal Hav-specific IgG(Hav IgG) from tenn pregnant women to their neonates. Methods : During Jan. 1st, 1998 to May. 31 tho 1998, we collected the 42 pairs of sera from pregnant women and umbilical cord of their neonates in Korea University Ansan Hospital. The serum levels of Hav IgG were measured by the RIA method. Results : 1) The seropositivities of Hav IgG were 78.6% in mothers and 81.0% in neonates. There was no statistical difference of mean antibody(Ab) levels between mothers and neonates. There was significant correlation of Ab levels between maternal sera and neonatal umbilical cord sera(correlation coefficient r=0.9285, P<0.001). 2) There were no significant correlations between neonatal Hav IgG level and other factors such as maternal age, gestational age and initial body weight of neonates. Conclusion : Seropositivities of Hav IgG tenn-pregnant women was comparable to those of their neonates. Pregnant women and their neonates can be protected from Hav infection.