986 resultados para Assisted reproductive Technologies


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La infertilidad es definida como la incapacidad para concebir después de un año de relaciones sexuales frecuentes es sin método anticonceptivo. Su incidencia está en 10% y 20% de las parejas a nivel mundial.Aunque las causas de infertilidad pueden ser múltiples entre ellas las endocrinológicas, la edad por disminución de la capacidad función ovárica. La evidencia científica establece que una de las principales causas es la presencia de alteraciones estructurales e inflamatorias a nivel uterino (30% ,40%) por lo cual muchos autores recomiendan la realización de histerosocopia previa a tratamiento de reproducción asistida. Se realizó un estudio de cohorte retrospectiva donde se incluyeron 205 mujeres con problemas de fertilidad que fueron llevadas a histeroscopia antes de iniciar algún tipo de tratamiento de reproducción asistida. En mujeres con infertilidad secundaria, la presencia de histeroscopia anormal aumenta la posibilidad de embarazo entre un 61% y un 74% comparado con mujeres con histeroscopia normal, siendo estadísticamente significativo. Los pólipos evidenciados en la histeroscopia y por patología fue mayor en mujeres en quien el tratamiento no fue exitoso. Respecto a los resultados de patología, se evidenció una diferencia estadísticamente significativa respecto a la presencia de endometritis crónica (p=0,0035) siendo más frecuente el grupo de mujeres que no quedaron embarazadas. La presencia de resultados anormales en la histeroscopia se asoció como factor protector para el éxito en la reproducción asistida en mujeres con problemas de fertilidad, y se asocian al éxito de la reproducción asistida en mujeres con infertilidad secundaria.

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ANTECEDENTES: El aislamiento de células fetales libres o ADN fetal en sangre materna abre una ventana de posibilidades diagnósticas no invasivas para patologías monogénicas y cromosómicas, además de permitir la identificación del sexo y del RH fetal. Actualmente existen múltiples estudios que evalúan la eficacia de estos métodos, mostrando resultados costo-efectivos y de menor riesgo que el estándar de oro. Este trabajo describe la evidencia encontrada acerca del diagnóstico prenatal no invasivo luego de realizar una revisión sistemática de la literatura. OBJETIVOS: El objetivo de este estudio fue reunir la evidencia que cumpla con los criterios de búsqueda, en el tema del diagnóstico fetal no invasivo por células fetales libres en sangre materna para determinar su utilidad diagnóstica.  MÉTODOS: Se realizó una revisión sistemática de la literatura con el fin de determinar si el diagnóstico prenatal no invasivo por células fetales libres en sangre materna es efectivo como método de diagnóstico.  RESULTADOS: Se encontraron 5,893 artículos que cumplían con los criterios de búsqueda; 67 cumplieron los criterios de inclusión: 49.3% (33/67) correspondieron a estudios de corte transversal, 38,8% (26/67) a estudios de cohortes y el 11.9% (8/67) a estudios casos y controles. Se obtuvieron resultados de sensibilidad, especificidad y tipo de prueba. CONCLUSIÓN: En la presente revisión sistemática, se evidencia como el diagnóstico prenatal no invasivo es una técnica feasible, reproducible y sensible para el diagnóstico fetal, evitando el riesgo de un diagnóstico invasivo.

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Many aspects of early embryonic development in the horse are unusual or unique; this is of scientific interest and, in some cases, considerable practical significance. During early development the number of different cell types increases rapidly and the organization of these increasingly differentiated cells becomes increasingly intricate as a result of various inter-related processes that occur step-wise or simultaneously in different parts of the conceptus (i.e., the embryo proper and its associated membranes and fluid). Equine conceptus development is of practical interest for many reasons. Most significantly, following a high rate of successful fertilization (71-96%) (Ball, 1988), as many as 30-40% of developing embryos fail to survive beyond the first two weeks of gestation (Ball, 1988), the time at which gastrulation begins. Indeed, despite considerable progress in the development of treatments for common causes of sub-fertility and of assisted reproductive techniques to enhance reproductive efficiency, the need to monitor and rebreed mares that lose a pregnancy or the failure to produce a foal, remain sources of considerable economic loss to the equine breeding industry. Of course, the potential causes of early embryonic death are numerous and varied (e.g. persistent mating induced endometritis, endometrial gland insufficiency, cervical incompetence, corpus luteum (CL) failure, chromosomal, genetic and other unknown factors (LeBlanc, 2004). However, the problem is especially acute in aged mares with a history of poor fertility in which the incidence of embryonic loss between days 2 and 14 after ovulation has been reported to reach 62-73%, and in which embryonic death is due primarily to embryonic defects rather than to uterine pathology (Ball et al., 1989; Carnevale & Ginther, 1995; Ball, 2000).

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Under the Public Bodies Bill 2010, the HFEA, cornerstone in the regulation of assisted reproduction technologies (ART) for the last twenty years, is due to be abolished. This implies that there is no longer a need for a dedicated regulator for ART and that the existing roles of the Authority as both operational compliance monitor, and instance of ethical evaluation, may be absorbed by existing healthcare regulators. This article presents a timely analysis of these disparate functions of the HFEA, charting reforms adopted in 2008 and assessing the impact of the current proposals. Taking assisted conception treatment as the focus activity, it will be shown that the last few years have seen a concentration on the HFEA as a technical regulator based upon the principles of Better Regulation, with little analysis of how the ethical responsibility of the Authority fits into this framework. The current proposal to abolish the HFEA continues to fail to address this crucial question. Notwithstanding the fact that the scope of the Authority's ethical role may be questioned, its abolition requires that the Government consider what alternatives exists - or need to be put in place - to provide both responsive operational regulation and a forum for ethical reflection and decision-making in an area which continues to pose regulatory challenges

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This chapter reconsiders critiques of pre-natal diagnosis in Disability Studies. Underlying assumptions about reproductive technologies are analysed to demonstrate that while many critiques of pre-natal diagnosis by Disability activists and theorists are concerned about children being the product of 'choice' through the selective effects of pre-natal diagnosis, the issue that reproductive technologies (such as IVF) themselves necessarily always already rely on 'choice' -- namely the choice for a 'biological' or 'own' child (different terms are used) -- is nowhere considered. The chapter considers several consequences of thinking through this issue and its implications.

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Purpose: the objective of the present investigation was to determine implantation and pregnancy rates in patients undergoing ICSI and treated with beta(2)-adrenergic agonists, considering the uterine-relaxing action of these agents.Methods: A total of 225 women undergoing ICSI at the Center for Human Reproduction, Sinha Junqueira Maternity Foundation, entered the study. Patient participation in each group was random, by drawing lots, using a randomization table previously elaborated for the study (2:2:1). The group I (90 women) received 10 mg of terbutaline daily for 15 days starting on the day of oocyte retrieval; group II (90 women) received 20 mg of ritodrine daily during the same period of time as group I; group III (45 patients) received no treatment and was used as control. The evaluation was interrupted in 3 patients of group I and in 30 patients of group II because of a high incidence of side effects.Results: Pregnancy, implantation, and miscarriage rates were not significantly different (p>0.05) between the three groups: 29.88%, 13.25%, and 26.9% for group I; 33.33%, 17.5%, and 10.0% for group II; 28.88%, 15.07%, and 15.38% for group III, respectively.Conclusions: the results of this study do not support the routine use of beta(2)-adrenergic agonists during the peri-implantation period in assisted reproductive technology cycles.

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Eutherian mammals share a common ancestor that evolved into two main placental types, i.e., hemotrophic (e.g., human and mouse) and histiotrophic (e.g., farm animals), which differ in invasiveness. Pregnancies initiated with assisted reproductive techniques (ART) in farm animals are at increased risk of failure; these losses were associated with placental defects, perhaps due to altered gene expression. Developmentally regulated genes in the placenta seem highly phylogenetically conserved, whereas those expressed later in pregnancy are more species-specific. To elucidate differences between hemotrophic and epitheliochorial placentae, gene expression data were compiled from microarray studies of bovine placental tissues at various stages of pregnancy. Moreover, an in silico subtractive library was constructed based on homology of bovine genes to the database of zebrafish - a nonplacental vertebrate. In addition, the list of placental preferentially expressed genes for the human and mouse were collected using bioinformatics tools (Tissue-specific Gene Expression and Regulation [TiGER] - for humans, and tissue-specific genes database (TiSGeD) - for mice and humans). Humans, mice, and cattle shared 93 genes expressed in their placentae. Most of these were related to immune function (based on analysis of gene ontology). Cattle and women shared expression of 23 genes, mostly related to hormonal activity, whereas mice and women shared 16 genes (primarily sexual differentiation and glycoprotein biology). Because the number of genes expressed by the placentae of both cattle and mice were similar (based on cluster analysis), we concluded that both cattle and mice were suitable models to study the biology of the human placenta. (C) 2011 Elsevier B.V. All rights reserved.

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The agonists of gonadotropin-releasing hormone (GnRH) were introduced in ovarian stimulation for in vitro fertilization to avoid a premature surge of luteinizing hormone. Although they are accompanied by some disadvantages, GnRH agonists have become well accepted in clinical practice, and their use is associated with increased rates of pregnancy. The development of GnRH antagonists capable of blocking the pituitary immediately offered a therapeutic option. Comparative studies between the two analogs have suggested that the use of antagonists is associated with a shorter duration of ovulatory stimulus and a decreased incidence of ovarian hyperstimulation syndrome, while the type of GnRH analogues used show no significant effects on the rates of pregnancy and live birth. However, GnRH agonists have other applications in assisted reproductive technology cycles than the pituitary downregulation.

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Objective: to expand the evaluation of a new ovarian response prediction index (ORPI), which was based on the AMH, AFC and age, and to verify its reability as a predictor of ovarian response to stimulation in assisted reproductive technology (ART) cycles. Methods: A total of 129 patients enrolled in the ICSI programme were included. The ORPI values were calculated by multiplying the AMH level (ng/ml) by the number of antral follicles (2-9 mm), and the result was divided by the age (years) of the patient (ORPI=(AMH × AFC)/Patient age). Results: Spearman's test revealed significant correlations (P<0.0001) between the ORPI and the number of oocytes collected and the number of follicles. Logistic regression revealed that ORPI values were significantly associated with the likelihood of collecting ≥4 oocytes (OR=45.56), ≥4 MII oocytes (OR=6.01) and ≥15 oocytes (OR=6.15; P<0.0001). Based on the ROC curves, the ORPI accurately predicted a low ovarian response (<4 oocytes retrieved; area under the curve (AUC):0.91), collection of ≥4 MII oocytes (AUC:0.85) and an excessive ovarian response (≥15 oocytes retrieved; AUC:0.89). Conclusions: The ORPI exhibited an excellent ability to predict a low ovarian response and a good ability to predict a collection of ≥ 4 MII oocytes, an excessive ovarian response. The ORPI might be used to improve the cost-benefit ratio of ovarian stimulation regimens by guiding the selection of medications and by modulating the doses and regimens according to the actual needs of the patients. © Todos os direitos reservados a SBRA - Sociedade Brasileira de Reprodução Assistida.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A biotecnologia aplicada à reprodução é uma ferramenta também importante para conservação de espécies ameaçadas de extinção. Algumas espécies de primatas não-humanos neotropicais têm sido amplamente agredidas por ações antrópicas, ocasionando a inclusão de 26 espécies brasileiras na lista oficial de animais ameaçados de extinção do IBAMA. As espécies de primatas não humanos Ateles belzebuth e Ateles paniscus, participantes do gênero Ateles, popularmente chamados de macaco-aranha, encontram-se particularmente ameaçadas. Poucos estudos são realizados acerca do status populacional destas espécies e menos ainda sobre dados reprodutivos e reprodução assistida. O presente trabalho pretendeu avaliar as características andrológicas de exemplares de primatas não humanos do gênero Ateles em cativeiro e comparar a performance dos diluentes TES e CEBRAN II, este último à base de ringer lactato, como criopreservadores de sêmen destas espécies. O experimento foi realizado utilizando 06 exemplares machos de primatas não humanos do gênero Ateles (02 exemplares de Ateles marginatus e 04 exemplares de Ateles paniscus) mantidos sob as mesmas condições de cativeiro no Centro Nacional de Primatas (CENP-SVS/MS), em Ananindeua, Pará. Os animais utilizados foram submetidos a exame clínico-andrológico e biometria testicular, antes da colheita seminal realizada por eletroejaculação. Foram realizadas avaliações físicoquímicas e de patologias espermáticas, além de avaliação de motilidade e vigor no sêmen a fresco e pós-diluição com os diluentes TES e CEBRAN II. As alíquotas de sêmen diluídas com os dois diluentes, na proporção 2:1, foram envasadas em minitubos com capacidade para 0,25 ml e criopreservados em nitrogênio líquido. Após descongelação, as doses envasadas foram avaliadas em teste de termo-resistência (T.T.R.). As médias de volume e concentração espermáticas obtidas foram, respectivamente, 1,94 ml (± 0,83) e 3.020.000 sptz/ml (±275,97). O pH 8 foi observado em todas as amostras e todos os exemplares apresentaram coagulação seminal. O índice de patologias espermáticas encontrados foi alto (69,8% ± 9,05) indicando que pode haver influência da sazonalidade reprodutiva nas características seminais encontradas nos animais deste experimento. Os resultados de avaliação de motilidade e vigor do sêmen a fresco, diluído e no T.T.R. não puderam ser analisadas estatisticamente, pois somente o sêmen de 03 animais demonstrou espermatozóides viáveis pós-descongelação, com resultados que sugerem que o diluente TES apresenta melhor eficiência na preservação de sêmen de Ateles do que o diluente CEBRAN II.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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