Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.190
Filtrar
1.
J Ovarian Res ; 15(1): 62, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35585606

RESUMO

BACKGROUND: Blastomere loss is a common phenomenon that occurs following cryopreservation. To date, studies have drawn conflicting conclusions regarding the impact of blastomere loss on pregnancy outcomes. Besides, limited information is available concerning the neonatal safety of embryos with blastomere loss. In the present study, we aimed to investigate the impact of blastomere loss on pregnancy and neonatal outcomes of vitrified/warmed Day3 cleavage-stage embryos in single embryo transfer cycles. METHODS: This retrospective cohort study included all vitrified/warmed D3 cleavage-stage single frozen-thawed embryo transfer (FET) cycles between April 2015 and February 2021. We compared pregnancy and subsequent neonatal outcomes between the intact embryos group and the blastomere loss group in single FET cycles. RESULTS: A total of 6287 single FET cycles were included in the study, in which 5873 cycles were classified into the intact embryo group and 414 cycles were classified into the blastomere loss group. The outcomes of the blastomere loss group were significantly inferior to those of the intact embryo group, in terms of implantation/biochemical pregnancy/clinical pregnancy/ongoing pregnancy rate and live birth rate per embryo transfer cycle/per clinical pregnancy. Further binary logistic regression confirmed that blastomere loss was negatively associated with live birth. Moreover, the blastomere loss group presented with an elevated early miscarriage rate. The neonatal conditions were broadly similar between the two groups. Additionally, multiple binary logistic regression analysis demonstrated that primary infertility and intracytoplasmic sperm injection (ICSI) were common influencing factors of blastomere loss (aOR 1.447, 95% CI 1.038-2.019, P = 0.029; aOR: 1.388, 95% CI: 1.044-51.846, P = 0.024). CONCLUSIONS: The transfer of vitrified/warmed D3 embryos with blastomere loss is related to impaired embryo developmental potentials and reduced probabilities of conception. Moreover, even if the embryos with blastomere loss have implanted and reached clinical pregnancies, they present with a lower possibility of developing to live birth owing to a higher early miscarriage rate. However, once the embryos with blastomere loss result in a live birth, no adverse neonatal outcomes are observed. Primary infertility and ICSI were found to be risk factors for blastomere loss.


Assuntos
Blastômeros , Resultado da Gravidez , Transferência de Embrião Único , Aborto Espontâneo/epidemiologia , Blastômeros/patologia , Criopreservação , Feminino , Humanos , Recém-Nascido , Infertilidade/epidemiologia , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Vitrificação
2.
Taiwan J Obstet Gynecol ; 61(3): 485-488, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35595442

RESUMO

OBJECTIVE: Oocyte vitrification has been developed as a promising alternative to slow freezing; however, the clinical outcome is highly operator dependent. From the past study, we know the timing of cryoprotectant exposure and understand that the intervals between the application of liquid nitrogen and thawing solution are crucial factors in the vitrification process. However, the optimal time intervals between hCG trigger and oocyte vitrification and equilibration remain unknown. This study aimed to evaluate the optimal intervals before and during modified vitrification. MATERIALS AND METHODS: This retrospective study included 66 patients undergoing vitrified-thawed oocyte cycles from June 2018 to May 2019. Oocyte in vitro maturation (IVM) is defined as the maturation in vitro of an immature oocyte collected using a standard pick up procedure. Oocytes were grouped into the following intervals: (1) human chorionic gonadotropin (hCG) trigger to oocyte vitrification (<38 h; 38-39 h; >39 h; IVM) (2) oocyte equilibration time (<10 min; 10-12 min; 12-15 min). The vitrification and warming procedures were performed following the steps as shown in the Cryotec method. RESULTS: A total of 390 mature oocytes were vitrified with the Cryotec method. The survival rates were not significantly different among the various intervals after the hCG trigger (97.59%; 95.54%; 100%); however, there was a trend of decreased survival rate in IVM group (66.67%). The oocyte survival rates were not significantly different among the various times of oocyte equilibration (96.77%; 97.33%; 95.42%). CONCLUSIONS: This was the first study to demonstrate no correlation between oocyte survival rate and the time intervals between hCG trigger and oocyte vitrification. Nor did the oocyte survival rate correlate with the various equilibration times during vitrification, as long as the oocyte was mature. In the future, large, prospective, randomized controlled studies will be required to confirm the clinical outcomes.


Assuntos
Criopreservação , Vitrificação , Gonadotropina Coriônica , Criopreservação/métodos , Humanos , Técnicas de Maturação in Vitro de Oócitos , Oócitos , Estudos Prospectivos , Estudos Retrospectivos
3.
Theriogenology ; 185: 121-126, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35397307

RESUMO

Intracytoplasmic sperm injection (ICSI), oocyte vitrification after ovum pick-up (OPU), and in vitro maturation are reproductive technologies with incredible potential for efficient cattle production. However, the developmental competence of embryos produced by ICSI using vitrified OPU oocytes remains unknown. Here, we aimed to evaluate the developmental competence of these embryos from the early embryo period to full term. The cleavage rate in the ICSI embryos using vitrified OPU oocytes during in vitro culture was significantly lower than those in control in vitro fertilized (IVF) embryos using fresh OPU oocytes (30.9 ± 4.5% v.s. 65.9 ± 7.0%) (P < 0.05), but the proportion of blastocysts to cleaved embryos was significantly higher than those of IVF embryos using vitrified OPU oocytes (55.9 ± 10.8% v.s. 23.2 ± 9.3%) (P < 0.05). To further investigate the transcription levels of genes related to cell differentiation in ICSI embryos using vitrified OPU oocytes, the relative abundance of mRNAs (OCT4, NANOG, SOX2, CDX2, GATA3, and IFNT) was analyzed by quantitative reverse-transcription PCR. There were no significant differences in the expression levels between ICSI embryos using vitrified OPU oocytes and control IVF embryos. Finally, developmental competence to term in ICSI embryos using vitrified OPU oocytes was examined by embryo transfer, and two healthy calves were born. These findings confirmed that ICSI and vitrification decrease developmental rates in vitro, but both procedures can lead to full-term development of bovine embryos. These results demonstrate that ICSI embryos using vitrification OPU oocytes are viable for cattle production.


Assuntos
Oócitos , Injeções de Esperma Intracitoplásmicas , Animais , Blastocisto , Bovinos , Fertilização In Vitro/veterinária , Injeções de Esperma Intracitoplásmicas/veterinária , Vitrificação
4.
Anim Reprod Sci ; 239: 106970, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35397403

RESUMO

The expansion of the use of in vitro production techniques has revolutionized the bovine embryo market. In the last decade, we have seen the number of in vitro produced (IVP) embryos surpass the number of in vivo-derived (IVD) embryos obtained worldwide. Concomitantly, other biotechnologies were also improved, following the global trend. Embryo cryopreservation has received special attention, as it is one of the tools capable of disseminating in vitro production. Currently, two protocols are available: slow freezing and vitrification. Both have advantages and disadvantages regarding their application and, many aspects need to be considered before their use. In this review, we discuss in vitro production market trends, cellular and molecular features involved in embryo response to cryopreservation, and addressed cryo-storage period and embryonic developmental stage on cryosurvival. In addition, we also presented an overview of some aspects that impact the pregnancy rate following transfer of fresh and cryopreserved IVP embryos.


Assuntos
Criopreservação , Transferência Embrionária , Animais , Bovinos , Criopreservação/métodos , Criopreservação/veterinária , Transferência Embrionária/métodos , Transferência Embrionária/veterinária , Feminino , Fertilização In Vitro/veterinária , Congelamento , Gravidez , Taxa de Gravidez , Vitrificação
5.
Cells ; 11(7)2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35406636

RESUMO

The cryopreservation of cells has been in routine use for decades. However, despite the extensive research in the field, cryopreservation of large tissues and organs is still experimental. The present review highlights the major studies of directional freezing and vitrification of large tissues and whole organs and describes the different parameters that impact the success rate of large tissue and organ cryopreservation. Key factors, such as mass and heat transfer, cryoprotectant toxicity, nucleation, crystal growth, and chilling injury, which all have a significant influence on whole-organ cryopreservation outcomes, are reviewed. In addition, an overview of the principles of directional freezing and vitrification is given and the manners in which cryopreservation impacts large tissues and organs are described in detail.


Assuntos
Criopreservação , Vitrificação , Crioprotetores/química , Crioprotetores/farmacologia , Congelamento
6.
Cells ; 11(7)2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-35406679

RESUMO

The demand for human bioengineered tissue constructs is growing in response to the worldwide movement away from the use of animals for testing of new chemicals, drug screening and household products. Presently, constructs are manufactured and delivered just in time, resulting in delays and high costs of manufacturing. Cryopreservation and banking would speed up delivery times and permit cost reduction due to larger scale manufacturing. Our objective in these studies was development of ice-free vitrification formulations and protocols using human bioengineered epithelial constructs that could be scaled up from individual constructs to 24-well plates. Initial experiments using single EpiDerm constructs in vials demonstrated viability >80% of untreated control, significantly higher than our best freezing strategy. Further studies focused on optimization and evaluation of ice-free vitrification strategies. Vitrification experiments with 55% (VS55) and 70% (VS70) cryoprotectant (CPA) formulations produced constructs with good viability shortly after rewarming, but viability decreased in the next days, post-rewarming in vitro. Protocol changes contributed to improved outcomes over time in vitro. We then transitioned from using glass vials with 1 construct to deep-well plates holding up to 24 individual constructs. Construct viability was maintained at >80% post-warming viability and >70% viability on days 1-3 in vitro. Similar viability was demonstrated for other related tissue constructs. Furthermore, we demonstrated maintenance of viability after 2-7 months of storage below -135 °C.


Assuntos
Crioprotetores , Vitrificação , Animais , Criopreservação/métodos , Crioprotetores/farmacologia , Congelamento
7.
PLoS One ; 17(4): e0267852, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35482795

RESUMO

A new mathematical model is proposed for the analysis of thermo-mechanics effects during isochoric cryopreservation. In that process, some ice crystallization in a fixed-volume container drives pressure elevation, which may be favorable to the preservation of biological material when it resides in the unfrozen portion of the same container. The proposed model is comprehensive, integrating for the first time concepts from the disparate fields of thermodynamics, heat transfer, fluid mechanics, and solid mechanics. The novelty in this study is in treating the cryopreserved material as having a pseudo-viscoelastic behavior over a very narrow temperature range, without affecting the mechanical behavior of the material in the rest of the domain. This unique approach permits treating the domain as a continuum, while avoiding the need to trace freezing fronts and sperate the analysis to liquid and solid subdomains. Consistent with the continuum approach, the heat transfer problem is solved using the enthalpy approach. The presented analysis focusses on isochoric cooling of pure water between standard atmospheric conditions and the triple point of liquid water, ice Ih, and ice III (-22°C and 207.4 MPa). The proposed model is also applicable to isochoric vitrification, by substituting the pseudo-viscoelastic material model with the real viscosity model of the vitrifying material. Results of this study display good agreement with phase-diagram data at steady state, and with experimental data from the literature. Furthermore, this study provides a venue to discussing experimentation aspects of isochoric cryopreservation. The proposed model is further demonstrated on a 3D problem, while discussing scale considerations, crystallization conditions, and transient effects. Notably, the new model can be used to bridge the gap between limited pressure and temperature measurements during cryopreservation and the analysis of the continuum. Arguably, this study presents the most advanced thermo-mechanics model to solve practical problems relating to isochoric cryopreservation.


Assuntos
Gelo , Isocoros , Criopreservação/métodos , Vitrificação , Água
8.
Theriogenology ; 184: 110-123, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35298950

RESUMO

The cryopreservation of mammalian oocytes and embryos has become an integral part of assisted reproduction in both humans and veterinary species. However, the methods used to cryopreserve bovine oocytes still have significant shortcomings. A wide variety of approaches has been used to try to improve and optimize methods of cryopreservation. However, these procedures employed are not always designed to specifically take account of the osmotic tolerance response of the cells according to the temperature and time of cryoprotectant (CPA) addition. When these properties are considered, optimal procedures for the addition of CPAs can be designed proactively. Based on in silico and in vitro osmotic observations, we propose shorter dehydration-based protocols at different temperatures (25°C vs. 38.5°C) towards defining an improved cryopreservation method. In vitro matured oocytes were exposed to equilibration solution (ES) at 25°C and 38.5°C and effects of optimized exposure times for each temperature were determined prior to vitrification/warming on oocyte spindle configuration, DNA fragmentation, and further embryo development. Upon exposure to standard ES (7.5% dimethyl sulfoxide + 7.5% ethylene glycol in TCM199 medium + 20% fetal bovine serum), original oocyte volume was recovered within 2 min 30 s at 38.5°C and 5 min 30 s at 25°C. In vitro matured oocytes were then exposed to the aforementioned cryoprotectants at both temperature/duration conditions and vitrified/warmed. While similar percentages of oocytes exhibiting a normally configured spindle and DNA fragmentation were observed in the fresh control group and oocytes vitrified at 38.5°C, significantly higher apoptosis rate and lower percentages of normal spindle configuration were observed in oocytes vitrified at 25°C when compared to control fresh oocytes. Similar cleavage rates and blastocyst yields were observed in the vitrified/38.5°C and fresh controls, while these rates were lower in vitrified/25°C. These results revealed that the limitation of the exposure time of the oocytes to the ES to the point of osmotic equilibrium volume recovery could be a more efficient approach to prepare them for vitrification. Therefore, exposure time to ES to 2 min 30 s at 38.5 °C appears to improve the quality of vitrified/warmed oocytes by protecting spindle integrity and reducing DNA fragmentation thus improving blastocyst rates and embryo quality.


Assuntos
Oócitos , Vitrificação , Animais , Criopreservação/métodos , Criopreservação/veterinária , Crioprotetores/farmacologia , Mamíferos , Oócitos/fisiologia , Temperatura
10.
Theriogenology ; 185: 16-23, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35344832

RESUMO

The cold-inducible RNA-binding protein (CIRBP) assists cells in adapting to new environmental conditions stabilizing specific mRNAs and promoting their translation. CIRBP participates in anti-apoptotic and anti-senescence processes, and its expression is induced by mild hypothermia, which may be advantageous to oocytes during vitrification. Several newly discovered small molecules, like zr17-2, mimic the effects of cold temperatures by increasing the expression of CIRBP at normothermia. This study aimed to evaluate the mRNA changes of a group of cold-inducible protein-encoding and apoptotic genes in response to exogenous supplementation of zr17-2 (experiment 1) or CIRBP (experiment 2) in vitro matured bovine oocytes and their cumulus cells. In experiment 1, cumulus-oocyte complexes (COCs) were randomly exposed to three concentrations of zr17-2 (1, 10, and 100 µM) during 24 h of in vitro maturation (IVM) under normothermia (38.5 °C) or mild hypothermia (34 °C) culture conditions. In experiment 2, COCs were randomly exposed to three concentrations of CIRBP (2, 4, and 6 µg/mL) or subjected to mild hypothermia (34 °C), followed by oocyte vitrification/warming after 20 h of IVM. The quantification of the selected gene transcript expression was performed separately in oocytes and cumulus cells by quantitative real-time PCR. We show that oocytes and cumulus cells exhibited similar mRNA expression responses to mild hypothermia and vitrification. However, minor differences were observed when COCs were exposed to exogenous supplementation with zr17-2 and CIRBP. In conclusion, the alterations observed in the mRNA expression in these experimental conditions may impact the quality of the cumulus-oocyte complexes in terms of vitrification and sublethal hypothermia challenges. In this sense, our results should complement other oocyte quality assessments for its application in future assisted reproductive techniques in the bovine species, including improving oocyte cryotolerance to vitrification.


Assuntos
Hipotermia , Vitrificação , Animais , Bovinos , Temperatura Baixa , Células do Cúmulo , Feminino , Hipotermia/metabolismo , Hipotermia/veterinária , Técnicas de Maturação in Vitro de Oócitos/métodos , Técnicas de Maturação in Vitro de Oócitos/veterinária , Oócitos/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
11.
Nat Med ; 28(4): 798-808, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35288694

RESUMO

Pancreatic islet transplantation can cure diabetes but requires accessible, high-quality islets in sufficient quantities. Cryopreservation could solve islet supply chain challenges by enabling quality-controlled banking and pooling of donor islets. Unfortunately, cryopreservation has not succeeded in this objective, as it must simultaneously provide high recovery, viability, function and scalability. Here, we achieve this goal in mouse, porcine, human and human stem cell (SC)-derived beta cell (SC-beta) islets by comprehensive optimization of cryoprotectant agent (CPA) composition, CPA loading and unloading conditions and methods for vitrification and rewarming (VR). Post-VR islet viability, relative to control, was 90.5% for mouse, 92.1% for SC-beta, 87.2% for porcine and 87.4% for human islets, and it remained unchanged for at least 9 months of cryogenic storage. VR islets had normal macroscopic, microscopic, and ultrastructural morphology. Mitochondrial membrane potential and adenosine triphosphate (ATP) levels were slightly reduced, but all other measures of cellular respiration, including oxygen consumption rate (OCR) to produce ATP, were unchanged. VR islets had normal glucose-stimulated insulin secretion (GSIS) function in vitro and in vivo. Porcine and SC-beta islets made insulin in xenotransplant models, and mouse islets tested in a marginal mass syngeneic transplant model cured diabetes in 92% of recipients within 24-48 h after transplant. Excellent glycemic control was seen for 150 days. Finally, our approach processed 2,500 islets with >95% islets recovery at >89% post-thaw viability and can readily be scaled up for higher throughput. These results suggest that cryopreservation can now be used to supply needed islets for improved transplantation outcomes that cure diabetes.


Assuntos
Diabetes Mellitus , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas , Trifosfato de Adenosina/metabolismo , Animais , Criopreservação/métodos , Crioprotetores/metabolismo , Crioprotetores/farmacologia , Diabetes Mellitus/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Suínos , Vitrificação
13.
Int J Mol Sci ; 23(6)2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35328464

RESUMO

INTRODUCTION: Spermatozoa cryopreservation is an important technique to preserve fertility for males. This study aimed at exploring the stability of epigenetics information in human spermatozoa, manipulated by two different technologies, freezing and vitrification. METHODS: Spermatozoa samples were distributed into three groups: 1. Fresh spermatozoa (control group), 2. Frozen spermatozoa, 3. Vitrified spermatozoa. Epigenetic differences of fresh and cryopreserved spermatozoa were evaluated using high-throughput RNA sequencing. RESULTS: Differentially expressed genes (DEGs) in frozen (1103 genes) and vitrified (333 genes) spermatozoa were evaluated. The bioinformatical analysis identified 8 and 15 significant pathways in groups of frozen and vitrified spermatozoa, respectively. The majority of these pathways are most relevant to immune and infectious diseases. The DEGs of the fertilization process are not detected during vitrification. The freezing process induces more down-regulation of genes and is relevant to apoptosis changes and immune response. CONCLUSION: Cryopreservation of human spermatozoa is an epigenetically safe method for male fertility preservation. Cryoprotectant-free vitrification can induce more minor biological changes in human spermatozoa, in comparison with conventional freezing.


Assuntos
Preservação do Sêmen , Vitrificação , Criopreservação/métodos , Crioprotetores/farmacologia , Congelamento , Humanos , Masculino , Preservação do Sêmen/métodos , Motilidade Espermática , Espermatozoides/fisiologia
14.
Cryo Letters ; 43(1): 1-9, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35315864

RESUMO

Density is a key thermophysical property, affecting the response of materials to temperature changes in different ways, consistent with the phase of state. In fluids, temperature variation across the domain leads to colder areas being heavier than warmer areas, where buoyancy effects drive fluid flow and thereby increase heat transfer. This phenomenon is known as natural heat convection, which in general is a more efficient heat transfer mechanism than heat conduction in the absence of flow. In solids, where the material is locked in place, colder areas tend to contract while warmer areas tend to expand, leading the material to deform. When this deformation is constrained by the geometry of the domain and/or its container, mechanical stresses develop. This phenomenon is known as thermomechanical stress (or thermal stress), which can lead to structural damage such as fractures. The picture becomes even more complex during vitrification (or glass formation), where the material gradually changes from liquid to an amorphous solid over a significant temperature range. There, due to temperature variation across the domain, fluid mechanics and solid mechanics effects may coexist. It follows that characterization of the density as a function of temperature is crucial for the analyses of thermal, fluid, and mechanical effects during cryopreservation, with the goals of protocol planning, optimization, and preserving structural integrity. For this purpose, the current study focuses on the density of the material and its companion property of thermal expansion. Specifically, this paper reviews literature data on thermal expansion of cryoprotective agents (CPAs), discusses the mathematical relationship between thermal expansion and density, and presents new calculated density data. This study focuses on the CPA cocktails DP6, VS55, M22, and their key ingredients at various concentrations, including DMSO, propylene glycol, and formamide. Data for DP6 combined with a selection of synthetic ice modulators (SIMs) are further presented.


Assuntos
Criopreservação , Crioprotetores , Criopreservação/métodos , Crioprotetores/química , Crioprotetores/farmacologia , Temperatura Alta , Temperatura , Vitrificação
15.
Cryo Letters ; 43(1): 10-17, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35315865

RESUMO

BACKGROUND: Vitrification increases the production of reactive oxygen species (ROS) and the antioxidants in the vitrification solution may be beneficial by reducing excessive ROS production. OBJECTIVE: To evaluate the effect of retinol supplementation in vitrification solution on viability, apoptosis and development-related gene expression in vitrified sheep preantral follicles. MATERIALS AND METHODS: Preantral follicles were isolated and randomly assigned into one of five groups: Group1, control fresh preantral follicles; Group 2, vitrification treatment; Group 3, vitrification + 2 µM retinol; Group 4, vitrification + 5 µM retinol; Group 5, vitrification + 10 µM retinol. Preantral follicles were placed in vitrification solutions and then plunged into liquid nitrogen (-196°C). After a week, the follicles were thawed and analyzed for follicular viability by trypan blue exclusion method and for gene expression. RESULTS: Vitrification with 5 µM retinol positively affected viability in comparison with vitrification without retinol (P < 0.05). There was no significant difference in viability among the Group 1, Group 2, Group 3 and Group 5. Expression of apoptotic genes BAX and Casp 3 were higher in the vitrified group, and vitrification with 5 µM retinol (Group 4) is comparable to the control fresh. Expressions of other apoptosis-related genes (i.e., BCL2L1, BAD and BAK) showed significant difference between the control fresh group and the vitrification group with 5 µM retinol. Expression of Annexin5 was also significantly different among various groups. The expression of development competence genes GDF-9 and BMP-15 were higher (P < 0.05) in the Group vitrified with 5 µM retinol. CONCLUSION: The supplementation of 5 µM retinol in vitrification solution was beneficial for the vitrification of ovine preantral follicles.


Assuntos
Vitamina A , Vitrificação , Animais , Apoptose , Criopreservação/métodos , Criopreservação/veterinária , Feminino , Folículo Ovariano , Ovinos , Vitamina A/farmacologia
16.
J Assist Reprod Genet ; 39(4): 873-882, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35119549

RESUMO

PURPOSE: Few studies explored whether prolonged cryo-storage after vitrification affects embryo competence and perinatal outcomes. This systematic review and meta-analysis aims at highlighting any putative impact of cryo-storage duration on cryo-survival, miscarriage, live birth and major malformations. METHODS: A systematic review was performed using MEDLINE (PubMed), ISI Web of Knowledge, Scopus and Embase databases up to June 2021. Data were combined to obtain a pooled OR, and meta-analysis was conducted using a random effects model. Out of 1,389 screened abstracts, 22 papers were assessed for eligibility, and 5 studies were included (N = 18,047 embryos). Prolonged cryo-storage was defined as > 12 months (N = 3389 embryos). Subgroup analysis was performed for untested vitrified cleavage stage embryos (N = 1739 embryos) and for untested and euploid vitrified blastocysts (N = 13,596 and 2712 embryos, respectively). RESULTS: Survival rate, miscarriage, live birth and major malformation rates were all similar in the two groups. CONCLUSION: These data further support the safety of long-term cryo-storage of human embryos beyond 12 months. This is reassuring for good prognosis patients with surplus embryos, couples seeking a second child from supernumerary embryos and women postponing the transfer for clinical or personal reasons.


Assuntos
Aborto Espontâneo , Vitrificação , Blastocisto , Criopreservação , Feminino , Humanos , Nascido Vivo , Gravidez , Taxa de Gravidez , Estudos Retrospectivos
17.
J Assist Reprod Genet ; 39(4): 987-993, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35217947

RESUMO

PURPOSE: To compare reproductive outcomes following a euploid embryo transfer, between those embryos vitrified-warmed twice to those vitrified-warmed once. METHODS: We retrospectively analysed 694 single euploid frozen embryo transfer cycles following preimplantation genetic testing for aneuploidy (PGT-A). For cycles in group 1 (N = 451), embryos were biopsied for PGT-A at blastocyst stage and vitrified. For cycles in group 2 (N = 146), embryos were vitrified at blastocyst stage, before being warmed and biopsied for PGT-A and vitrified again. For cycles in group 3 (N = 97), embryos were vitrified on day-3, before being warmed, cultured to day-5 and biopsied for PGT-A and re-vitrified. RESULTS: The pregnancy, clinical pregnancy and livebirth rate in group 2 were not statistically different to group 1 (pregnancy rate, adjusted OR 1.09, 95% CI 0.62-1.91; clinical pregnancy, aOR 0.89, 95% CI 0.58-1.37; live birth rate, aOR 0.85, 95% CI 0.56-1.28). There was also no significant difference between group 3 and group 1, with similar pregnancy rate (aOR 1.22, 95% CI 0.74-1.99), clinical pregnancy rate (aOR 1.21, 95% CI 0.75-1.96) and live birth rate (aOR 1.15, 95% CI, 0.73-1.80). There was no significant difference in miscarriage rates between all three groups. The age at the oocyte collection, embryo quality and day of biopsy were associated with pregnancy, clinical pregnancy and live birth rate. CONCLUSION: This study suggests that vitrifying and warming embryos twice at blastocyst or at cleavage and then blastocyst stage, can lead to similar reproductive outcomes to embryos vitrified-warmed once, after a single euploid embryo transfer.


Assuntos
Coeficiente de Natalidade , Vitrificação , Aneuploidia , Blastocisto/patologia , Criopreservação , Transferência Embrionária , Feminino , Humanos , Nascido Vivo , Gravidez , Taxa de Gravidez , Estudos Retrospectivos
18.
Reprod Biomed Online ; 44(3): 486-493, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35177340

RESUMO

RESEARCH QUESTION: Does the endometrial aspiration of ultrasound-invisible fluid immediately preceding embryo transfer affect IVF/vitrified-warmed embryo transfer outcomes? DESIGN: A prospective matched cohort study was conducted in 96 women and 96 control participants to assess the effect on pregnancy outcomes of endometrial aspiration performed immediately before embryo transfer. This study was carried out at a university-affiliated assisted reproductive medical centre between January 2019 and December 2019. Patients were divided into two groups. The EA group had cycles with endometrial aspiration of ultrasound-invisible fluid performed before embryo transfer and the non-EA group featured cycles without endometrial aspiration. The EA group was matched by propensity score with the non-EA group in a 1:1 ratio. The EA group consisted of 99 participants before and 96 participants after propensity score matching. There were 203 and 96 participants in the non-EA group before and after propensity score matching. RESULTS: No significant differences were detected in the baseline characteristics and cycle characteristics of the EA and non-EA groups. No significant between-group differences were found in reproductive outcomes in the overall population. Subgroup analysis of blastocyst transfer cycles showed the implantation rate was significantly higher in the EA group (61 women per group, 57.1% versus 40.8%, relative risk 1.40, 95% confidence interval 1.04-1.88; P = 0.022). Live birth rate, clinical pregnancy rate, ongoing pregnancy rate and multiple pregnancy rate were not different among the groups. CONCLUSIONS: Endometrial aspiration immediately preceding embryo transfer does not affect IVF/vitrified-warmed embryo transfer outcomes. Interestingly, it might improve the vitrified-warmed blastocyst implantation rate. Randomized controlled trials are needed to confirm this result.


Assuntos
Transferência Embrionária , Fertilização In Vitro , Estudos de Coortes , Criopreservação , Feminino , Humanos , Masculino , Gravidez , Taxa de Gravidez , Estudos Prospectivos , Estudos Retrospectivos , Vitrificação
19.
Reprod Biomed Online ; 44(3): 393-410, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35135728

RESUMO

RESEARCH QUESTION: What is the effect on mouse fetal gene expression of combined antioxidants (acetyl-L-carnitine, N-acetyl-L-cysteine and alpha-lipoic acid; A3) when used in culture media and vitrification/warming solutions? DESIGN: A laboratory-based analysis of an animal model. Embryo transfers were conducted on in-vivo-flushed blastocysts, or blastocysts cultured or vitrified with and without A3. Transcriptional profiles of E14.5 fetal liver and placental tissue in all groups were quantified using RNA-Seq and functional analyses (gene ontology [GO] biological processes and Kyoto Encyclopedia of Genes and Genomes [KEGG] pathway analysis). RESULTS: Both in-vitro culture in the presence of 20% oxygen and vitrification of blastocysts significantly perturbed fetal liver and placental gene expression. Notably, supplementation of in-vitro culture media or vitrification/warming solutions with A3 reduced the number of differentially expressed genes (DEG) and biological processes altered, establishing a more in-vivo-like gene expression profile, particularly within the E14.5 placenta. Specifically, A3 supplementation significantly reduced the expression of genes associated with pre-eclampsia and intrauterine growth restriction, along with genes involved in metabolism, cell senescence and cancer associated pathways. However, despite these improvements, several biological processes remained over-represented following both in-vitro culture and vitrification, even in the presence of A3. CONCLUSION: Both in-vitro culture in the presence of 20% oxygen and vitrification of blastocysts significantly perturbed fetal liver and placental gene expression, with the number of DEG greater following vitrification. Supplementation with A3 reduced the number of DEG and biological processes altered, establishing a more in-vivo-like gene expression profile, particularly in the placenta. Notably, A3 supplementation of in-vitro culture media significantly reduced the expression of genes associated with pre-eclampsia and intrauterine growth restriction.


Assuntos
Antioxidantes , Pré-Eclâmpsia , Animais , Antioxidantes/farmacologia , Blastocisto , Criopreservação , Meios de Cultura , Suplementos Nutricionais , Técnicas de Cultura Embrionária , Feminino , Retardo do Crescimento Fetal/genética , Expressão Gênica , Humanos , Camundongos , Oxigênio , Placenta , Gravidez , Vitrificação
20.
Reprod Biomed Online ; 44(4): 630-635, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35151577

RESUMO

RESEARCH QUESTION: What is the clinical importance of vitrified-warmed blastocyst transfer timing if performed on days 5, 6 and 7 after detecting the LH surge using urine tests? DESIGN: Between 2013 and 2019, 2080 vitrified-warmed blastocyst transfers in a true natural cycle were performed and later analysed at the Department of Reproductive Medicine, University Medical Centre Maribor, Slovenia. Urine LH tests were performed twice daily to monitor the onset of the LH surge. Vitrified-warmed blastocyst transfer (frozen embryo transfer [FET]) was performed on day 5 (group 1), 6 (group 2) or 7 (group 3) after the LH surge in 18%, 77% and 4% of cycles, respectively. The patient and cycle characteristics among the groups were compared using the Cochran-Mantel-Haenszel test and respective generalized linear mixed models. Propensity score matching was used to adjust for potential differences among the groups. RESULTS: There were no statistically significant differences between groups 1, 2 and 3 in the cycle and patient characteristics, clinical pregnancy rate (38% versus 39% versus 31%), implantation rate (34% versus 36% versus 31%), miscarriage rate (7% versus 9% versus 7%) and delivery rate (31% versus 31% versus 24%). The day of FET after the LH surge detected using a urine test was not significantly associated with live births. CONCLUSIONS: The results of the current study suggested that the vitrified-warmed blastocyst transfer could be scheduled on day 5, 6 or 7 after a positive LH urine test without having a significant impact on the clinical outcome.


Assuntos
Transferência Embrionária , Nascido Vivo , Blastocisto , Criopreservação/métodos , Implantação do Embrião , Transferência Embrionária/métodos , Feminino , Humanos , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Vitrificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...