• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.119-125
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• 2011

Implantation of an embryo occurs during the mid-secretory phase of the menstrual cycle, known as the "implantation window." During this implantation period, there are significant morphologic and functional changes in the endometrium, which is followed by decidualization. Many immune cells, such as dendritic and natural killer (NK) cells, increase in number in this period and early pregnancy. Recent works have revealed that antigen-presenting cells (APCs) and NK cells are involved in vascular remodeling of spiral arteries in the decidua and lack of APCs leads to failure of pregnancy. Paternal and fetal antigens may play a role in the induction of immune tolerance during pregnancy. A balance between effectors (i.e., innate immunity and helper T [Th] 1 and Th17 immunity) and regulators (Th2 cells, regulatory T cells, etc.) is essential for establishment and maintenance of pregnancy. The highly complicated endocrine-immune network works in decidualization of the endometrium and at the fetomaternal interface. We will discuss the role of immune cells in the implantation period and during early pregnancy.

• Development and Reproduction
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• v.14 no.3
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• pp.207-214
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• 2010

The tremendous changes of uterine endometrium are observed during early pregnancy and protease and their inhibitors are involved in regulation of cell proliferation and remodeling of the tissues through remodeling the extracellular matrix (ECM). Some of the proteases and protease inhibitors have been suspected to a factor in endometrial changes but many parts of their expression profiles and the physiological roles are not uncovered. To evaluate the functional roles of them, in this study the expression profiles of proteases and protease inhibitors were analyzed using real-time quantitative PCR analysis. Mmp9 (matrix metalloproteinase 9) mRNA levels peaked on day 4 at the time of implantation. On the other hand, Ela2 (neutrophil elastase, NE) mRNA levels were peaked on day 2 of pregnancy. Its expression were decreased until day 4 of pregnancy but increased rapidly until day 7 of pregnancy and decreased again. NE inhibitor Slpi (secretory leukocyte protease inhibitor, SLPI) mRNA levels were related with the implantation stage and with the levels of Ela2. At the time of implantation the expression levels of Slpi mRNA were about 5 times higher than the Ela2 mRNA in the uterus. In the implantation stage embryos, Mmp9 specific mRNA was only detected at the blastocyst. On the other hand, the expression level of SLPI was higher than that of the Ela2 mRNA at blastocyst and 4.5 day p.c. embryos. Based on these results it is suggested that MMP9, SLPI, and NE have important physiological role in embryo implantation both in uterus and embryos.

• 대한생식의학회:학술대회논문집
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• 2006.06a
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• pp.154.2-154.2
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• 2006

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.339-344
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• 1999

Objective: To evaluate incidence of microbial growth from the tip of the embryo transfer catheter after embryo transfer in relation to clinical pregnancy rate following in-vitro fertilization and embryo transfer. Method: This study was performed prospectively at the time of transcervical embryo transfer following conventional in-vitro fertilization and intracytoplasmic sperm injection procedures. Sixty three patients were enrolled in this study. Microbiological cultures were performed on endocervical swabs and embryo transfer catheter tips. Results: Positive microbial growths were observed from endocervical swabs in 45 (71.4%) women and from catheter tips in 30 (47.6%) women. There was no statistically significant difference seen in the mean number of oocytes fertilized or number and grade of embryos transferred between the group of patients without growth and the group of patients with positive microbial growth from catheter tips. The clinical pregnancy rate were 30.3% in the group of patients without growth and 13.3% in the group with positive microbial growth from catheter tips. This difference in clinical pregnancy rates was statistically significant. Conclusion: Our finding is that microbial contamination at embryo transfer may influence implantation rates. The major questions arising from our finding are whether eradication of endocervical micro-organisms is possible and whether their eradication will improve implantation rates.

• The Journal of Korean Medicine
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• v.21 no.3
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• pp.166-173
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• 2000

Objectives : These experiments were undertaken to evaluate the effect of the administration on Korean herbal medicines, Kyoaekungkue-tang, Bojungykki-tang, Kungso-san, Antae-eum, and Antaegumchul-tang, on the reproductive functions in pregnant mice. Methods : Prepared herbal medicines(Kyoaekungkue-tang, Bojungykki-tang, Kungso-san, Antae-eum, Antaegumchul-tang) were administered to three different pregnant staged mice. We designed 3 experiments as follows; prepared herbal medicine administered from ovulation to embryo implantation (Experiment I), or administered after implantation to fetal organogenesis (Experiment II) and lastly administered from end of organogenesis to parturition (Experiment III). At day 14 of pregnancy, the whole uteri of half of the treated mice were retrieved from the Experiment I and in the Experiment II the implantation and mean weight of the fetuses were examined. The mean numbers of offspring, sex ratio and mean birth weight were examined in the other half of the mice. Results : The results from these studies were summarized as followed; 1. From the experiment I (administered from ovulation to embryo implantation), the no. of implantation between control and herbal medicine treated groups were shown similar results. Litter size after parturition was significantly decreased in the herbal medicine treated groups, except for Antaegumchul-tang. However, the mean weight of offspring after parturition showed a tendency to increase in the three herbal medicine treated groups. 2. From the experiment II (administered after implantation to fetal organogenesis), the implantation rates from the herbal medicine treated groups increased more significantly than that of the control Also, litter size and birth weight in the herbal medicine groups, except Antaeeum, increased more significantly than that of the control group. 3. From the experiment III group (administered after organogenesis to parturition), the mean number of offspring in Kyoaekungkue-tang and Antaegumchul-tang treated groups were significantly increased than that of control However, the litter size of the Kungso-san treated mice was significantly decreased compared with that of the control group. Compared with the control and other herbal treated groups, the mean weight of fetuses after parturition in the Kyoaekungkue-tang and Antaegumchul-tang treated groups increased significantly. Conclusions : From these results, it can be concluded that Antaegumchul-tang showed more beneficial effects on the reproductive functions, implantation, maintenance of pregnancy, litter size and mean weight than other herbs.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.4
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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.

• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.471-484
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• 2009

The peri-implantation period in mammals is critical with respect to survival of the conceptus (embryo/fetus and associated extraembryonic membranes) and establishment of pregnancy. During this period of pregnancy, reciprocal communication between ovary, conceptus, and endometrium is required for successful implantation and placentation. At this time, interferon tau (IFNT) is synthesized and secreted by the mononuclear trophectodermal cells of the conceptus between days 10 and 21~25. The actions of IFNT to signal pregnancy recognition and induce or increase expression of IFNT-stimulated genes (ISGs), such as ISG15 and OAS, are mediated by the Type I IFN signal transduction pathway. This article reviews the history, signaling pathways of IFNT and the uterine expression of several IFNT-stimulated genes during the peri-implantation period. Collectively, these newly identified genes are believed to be critical to unraveling the mechanism(s) of reciprocal fetal-maternal interactions required for successful implantation and pregnancy.

• Molecules and Cells
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• v.22 no.3
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• pp.262-268
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• 2006

During endometrial differentiation the extracellular matrix (ECM) changes dramatically to prepare for implantation of the embryo. However, the genes regulating the ECM build-up in the uterine endometrium during early pregnancy are not well known. Using the PCR-select cDNA subtraction method, dermatopontin was identified in the uterus of a pregnant mouse on day 4 of gestation. Dermatopontin mRNA increased dramatically on day 3, and was at its highest level at the time of implantation. Administration of RU 486 significantly inhibited mRNA expression by day 4 of gestation, but ICI 182,780 did not. Progesterone markedly induced dermatopontin expression in ovariectomized uteri within 4 h of administration, whereas estrogen had little effect. In silico analysis revealed progesterone receptor binding sites in the dermatopontin promoter region. Decidualization did not induce expression of dermatopontin; instead dermatopontin mRNA became strongly localized at the interimplantation site. In situ hybridization revealed that expression gradually decreased in the luminal epithelial cells as pregnancy progressed, whereas it increased in the stromal cells. The pattern of localization and the changes of intensity of dermatopontin mRNA coincided with those of collagen. Collectively, these results strongly suggest that dermatopontin expression is steroid-dependent. They also suggest that, at the time of implantation, dermatopontin expression is primarily regulated spatio-temporally by progesterone via progesterone receptors, and is modulated by the decidual response during implantation. Dermatopontin may be one of the regulators used to remodel the uterine ECM for pregnancy.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.85-85
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• 2002

Pregnancy block by male pheromones in mice differs in incidence depending on the combination of strains. Female mice of BALB/cA strain mated with BALB/cA males show a 100% pregnancy block when exposed to males of inbred strain DDK shortly after copulation (Chung et al., Biol Reprod 1997). In the present study, BALB/cA females mated with the males of other strains (CBA/J, C3H/HeN, C57BL/6Cr, and IXBL) showed higher pregnancy rates (66.6-87.5%) even when they were exposed to DDK males. In the pharmacological induction of pregnancy block with dopamine agonist (Bromocriptine, 4mg/kg BW), BALB/cA females mated with BALB/cA males showed a 100% pregnancy block. In contrast, BALB/cA females mated with CBA/J, C3H/HeN, and C57BL/6Cr males showed higher pregnancy rates (40-70%). These results suggest that the better pregnancy rate of BALB/cA females mated with alien males may be due to the stronger viability of F 1 embryos. This interpretation was confirmed by an embryo transfer experiment in which a higher implantation rate was observed when BALB/cA embryos grown in BALB/cA females exposed to BALB/cA males were transferred into recipient BALB/cA females exposed to DDK males. These results suggest that the embryonic genotype or viability of the embryo is one factor contributing to the occurrence of pregnancy block by male pheromones in mice.

• Journal of Embryo Transfer
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• v.4 no.1
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• pp.28-34
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• 1989

These experiments were carried out to determine the effect of cell stage in embryo bisection on the sub-Sequent in vitro and in vivo development in mouse. The embryos of ICR mouse were microsurgicaily bisected at 2-cell, 4-cell, 8-cell, morula and blastocyst stage using a microsurgical blade attached a micromanipulator. These demi-embryos without zona pellucida were cultured up to blastocyst stage and transferred to pseudopregnant mice, and the development of these demi-embryos was compared with the results of intact embryos of the corresponding cell stage. The successful rate of mouse embryo bisection at 4-cell stage (59.0%) was significantly (p <0.05) lower than those at 8-cell (75.6%), 2ce11 (80.7%) or morula stage (84.8%), and highest at blastocyst stage (95.7%). When the bisected embryos without any damage from microsurgery were cultured in vitro up to blastocyst,the in vitro de'velopment of demi-embroys bisected at morula to blastocyst was 91.6 to 95.3%, which was similar to the culture result of intact embryos of corresponding stage. However, the in vitro development of demi-em-bryos bisected at 2- to 8-cell stage was signiflcantiy (p <0.05) lower.The post-transfer implantation rate of demi-embryos developed in vitro to eu-blastocyst were 19.6 and 25.4% in demi-embryos bisected at morula and blastocyst stage,respectively and not significantly (P <0.05)different from the result of intact embryos of the same stage. However, the implantation rates of demi-embryos bisected at 2- or 8-cell stage were significantly (P <0.05) lower than the result from the intact embryos of the corresponding stage.