26 resultados para Assisted Reproductive Technologies

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Background: It is not well established whether the increased number of leukocytes in the seminal fluid impairs the outcomes of assisted reproductive technology (ART). This investigation analysed the outcomes of the intracytoplasmic sperm injection (ICSI) and intracytoplasmic morphologically selected sperm injection (IMSI) cycles in couples in which the male partner exhibited leukocytospermia.Methods: A total of 100 cycles in 100 couples were included in this study. For the ICSI or IMSI procedures, the patients were divided into two groups according to the presence or absence of leukocytospermia and then matched by (female) age:- ICSI: Group I (n = 25): Leukocytospermia - semen samples with a leukocyte count of greater than or equal to 1 x 10(6)/mL; and Group II (n = 25): Non-leukocytospermia - semen samples with a leukocyte count < 1 x 10(6)/mL.- IMSI: Group I (n = 25): Leukocytospermia; and Group II (n = 25): Non-leukocytospermia.The endpoints included the rates of fertilisation, implantation, clinical pregnancy, miscarriage, ongoing pregnancy and live birth. Student's t-tests, Mann-Whitney tests and Chi-square tests were performed, and P < 0.05 was considered significant.Results: The data from the ICSI groups showed that leukocytospermia did not have a negative influence on the rates of fertilisation (Group I: 57.9+/-30.2%, Group II: 61.9+/-27.7%; P = 0.74), implantation (Group I: 12.3%; Group II: 13.5%; P = 0.93), clinical pregnancy (Group I: 24%; Group II: 24%; P = 1.0), miscarriage ( Group I: 0, Group II: 0), ongoing pregnancy (Group I: 24%; Group II: 24%; P = 1.0), or live births (Group I: 24%; Group II: 24%; P = 1.0). Similarly, the data from the IMSI groups also showed that the leukocytospermia did not have a negative influence on the rates of fertilisation (Group I: 67.6+/-24.6%, Group II: 59.5+/-28.1%; P = 0.36), implantation (Group I: 17.5%; Group II: 16.7%; P = 0.90), clinical pregnancy (Group I: 28%; Group II: 24%; P = 1.0), miscarriage (Group I: 14.3%; Group II: 0; P = 0.33), ongoing pregnancy (Group I: 24%; Group II: 24%; P = 1.0), or live births (Group I: 24%, 6/25; Group II: 24%, 6/25; P = 1.0).Conclusions: The results indicate that the leukocytospermia may not have a negative effect on the outcomes of ICSI or IMSI cycles. Nevertheless, it seems that it is necessary to more precisely determine the effects, if any, of seminal leukocytes on fertilisation and implantation processes. Such efforts will help to establish a more reliable leukocyte threshold, which could eventually demonstrate whether there is a negative influence on the ART procedures.

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Genomics has been propagated as a paradigm shifting innovation in livestock during the last decade. The possibility of predicting breeding values using genomic information has revolutionized the dairy cattle industry and is now being implemented in beef cattle. In this paper we discuss how genomics is changing cattle breeding through genomic selection, and how this change is creating new ways to articulate assisted reproduction technologies with animal breeding. We also debate that the scientific community is still starting the long journey to reveal the functional aspects of the cattle genome, and that knowledge in this field is the frontier to a whole new venue for the development of novel applications in the livestock sector.

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The majority of beef cow herds in South America are constituted by Bos indicus females, which have particular reproductive features that contribute to reduced reproductive efficiency compared with that of B. taurus cohorts. Hence, several alternatives to enhance reproductive efficiency of B. indicus heifers and cows have been developed to address their inherent reproductive shortcomings. These research-based technologies are being described in detail within this chapter and have already made an impact on South American B. indicus-based production systems. These include the following: (a) hormonal protocols to induce puberty in nulliparous heifers or estrous cyclicity in postpartum cows to maximize their reproductive performance during the subsequent breeding season, (b) hormonal protocols to synchronize estrus and/or ovulation in B. indicus females to exploit their reproductive responses to artificial insemination, and (c) genetic and environmental factors that influence reproductive success in beef herds, including reproductive diseases and excitable temperament of B. indicus females, that have been investigated to support/promote the development of appropriate mitigation technologies.

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The purpose of this investigation was to verify the efficacy of recombinant LH supplementation for controlled ovarian stimulation in GnRH-antagonist protocol for assisted reproductive technologies cycles. Search strategies included on-line surveys of databases from 1990 to 2006. In this review and meta-analysis, the observed advantages for the LH supplementation protocol were a higher serum estradiol levels on the day of hCG administration and a higher number of mature oocytes. However, there were no differences observed in the total amount of r-FSH administered, days of stimulation, number of oocyte retrieved, the clinical pregnancy rate per oocyte retrieval, the implantation rate and miscarriage rate. This result demonstrates that the association of r-LH with r-FSH may prevent any decrease in estradiol after antagonist administration and a significant higher number of mature oocytes was obtained. Nevertheless, additional randomized controlled trials are needed confirm these observations.

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Pós-graduação em Medicina Veterinária - FCAV

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

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Despite the efforts made to improve the production of bovine embryos in vitro, their efficiency is still low, since only 30-40% of developed blastocysts are obtained from oocytes after in vitro maturation (IVM), fertilization and cultured embryos. Assisted reproductive technologies have a limiting impact due a lack of oocytes capable to fertilization.The comprehension of mechanism involved in oocyte maturation are crucial to establish a culture system that allows a larger number production of good quality embryos. The study of the early stages of oocyte and follicle development in vivo is important for a better understanding of the molecular pathways that regulate oogenesis, folliculogenesis and oocyte maturation. Thus the physiological biochemical and molecular mechanisms involved in maturation may contribute to the increased efficiency of in vitro embryo production. Therefore, the aim of this literature review is to understand the basic mechanisms that underlie oocyte maturation in cattle, since oocyte and follicle cells in vivo formation to its use in the in vitro environment.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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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)