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Dive into the research topics where Claudio Álvarez is active.

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Featured researches published by Claudio Álvarez.


Fertility and Sterility | 2009

Antral follicle count (AFC) can be used in the prediction of ovarian response but cannot predict the oocyte/embryo quality or the in vitro fertilization outcome in an egg donation program.

M.A.B. Melo; Nicolás Garrido; Claudio Álvarez; José Bellver; Marcos Meseguer; A. Pellicer; J. Remohí

OBJECTIVE To verify whether the antral follicle count (AFC) could predict ovarian response, oocyte/embryo quality, and IVF outcome. DESIGN Prospective study. SETTING Instituto Universitario-Instituto Valenciano de Infertilidad, Valencia, Spain. PATIENT(S) One thousand seventy-four donors and 975 oocyte recipient cycles. INTERVENTION(S) Controlled ovarian hyperstimulation (COH), endometrial preparation, IVF/intracytoplasmic sperm injection, ET. MAIN OUTCOME MEASURE(S) COH and oocyte/embryo quality parameters and IVF outcome. RESULT(S) We observed lower E(2) levels and fewer mature retrieved oocyte numbers among donors who showed an AFC that was <10. These donors also showed significantly higher cancellation and no-donation rates; poor and/or insufficient response was the principal cause (82%). However, there were no differences among the groups regarding embryo development parameters and IVF outcome. CONCLUSION(S) AFC is a noninvasive and simple tool that can improve the oocyte donors selection of an egg donation program. This study suggests that AFC is a good predictor of ovarian response but cannot be used to predict oocyte/embryo quality or IVF outcome.


Reproductive Biomedicine Online | 2009

Prevention of OHSS – dopamine agonists

Cristiano Busso; Juan A. Garcia-Velasco; Raúl Gómez; Claudio Álvarez; Carlos Simón; Antonio Pellicer

Abstract Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of ovulation induction, which may seriously affect the patients health, with 0.1–2.0% of the patients developing severe forms of the syndrome. OHSS signs and symptoms are direct consequences of fluid shift from capillaries to the third space due to increased vascular permeability. The mechanisms of OHSS pathophysiology remain unknown but evidence obtained in animal models prove that vascular endothelial growth factor (VEGF) is directly involved and the inhibition of the VEGF system could prevent OHSS from occurring. Dopamine agonists impede the phosphorylation of the VEGF receptor 2 and reduce the incidence and severity of OHSS with a safe clinical profile. As far as is known, this is the first pathophysiological approach for treatment and prevention of OHSS.


Journal of Assisted Reproduction and Genetics | 2018

Polycystic ovary syndrome throughout a woman’s life

José Bellver; Luis Rodriguez-Tabernero; Ana Robles; Elkin Muñoz; Francisca Martínez; J. Landeras; Juan A. Garcia-Velasco; Juan Fontes; Monica Alvarez; Claudio Álvarez; Belen Acevedo

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-aged women and the main cause of infertility due to anovulation. However, this syndrome spans the lives of women affecting them from in-utero life until death, leading to several health risks that can impair quality of life and increase morbidity and mortality rates. Fetal programming may represent the beginning of the condition characterized by hyperandrogenism and insulin resistance which leads to a series of medical consequences in adolescence, adulthood, and old age. Menstrual and fertility problems evolve into metabolic complications as age advances. An early and precise diagnosis is important for an adequate management of PCOS, especially at the extreme ends of the reproductive lifespan. However, many different phenotypes are included under the same condition, being important to look at these different phenotypes separately, as they may require different treatments and have different consequences. In this way, PCOS exhibits a great metabolic complexity and its diagnosis needs to be revised once again and adapted to recent data obtained by new technologies. According to the current medical literature, lifestyle therapy constitutes the first step in the management, especially when excess body weight is associated. Pharmacotherapy is frequently used to treat the most predominant manifestations in each age group, such as irregular menses and hirsutism in adolescence, fertility problems in adulthood, and metabolic problems and risk of cancer in old age. Close surveillance is mandatory in each stage of life to avoid health risks which may also affect the offspring, since fetal and post-natal complications seem to be increased in PCOS women.


Reproductive Biomedicine Online | 2007

Effect of a sharp serum oestradiol fall before HCG administration during ovarian stimulation in donors

Ana Cobo; Ernesto Bosch; Claudio Álvarez; María José de los Santos; Antonio Pellicer; José Remohí

The current study evaluated how a sudden fall in serum oestradiol during ovarian stimulation in donors affects recipient outcome. After the assessment of pregnancy rate in cases of oestradiol falls of <10 or > or =10% (57.0 versus 45.6%), <20 or > or = 20% (55.2 versus 44.9%), <25 or > or =25% (57.2 versus 41.2%), and < 30 or > or =30% (57.1 versus 32.0%; P < 0.05), a significantly lower pregnancy rate was observed when the fall was > or =30%. Therefore, the study group (n = 25) included recipients who received oocytes from donors with a fall of > or =30%, and the control group included patients (n = 197) in which the fall in oestradiol was <30% and all cases with no fall in oestradiol concentrations. Pregnancy rates in both groups were 32.0 versus 57.1%; P < 0.05. The number of morphologically normal oocytes was similar (14.2 versus 18.1%) and good quality embryos was lower (8.0 versus 21.0%; P < 0.05) for study group. This seems related to a lower capability of the embryos to implant (15.2 versus 37.4%; P < 0.001). These data indicate that a fall of > or =30% in serum oestradiol concentration during ovarian stimulation in donors negatively affects pregnancy rates and embryo quality in recipients. In these cases, cycle cancellation should be considered.


The Journal of Clinical Endocrinology and Metabolism | 2007

Dopamine Agonist Cabergoline Reduces Hemoconcentration and Ascites in Hyperstimulated Women Undergoing Assisted Reproduction

Claudio Álvarez; Luis Martí-Bonmatí; Edurne Novella-Maestre; Roberto Sanz; Raúl Gómez; Manuel Fernández-Sánchez; Carlos Simón; A. Pellicer


Human Reproduction | 2007

The role of thrombophilia and thyroid autoimmunity in unexplained infertility, implantation failure and recurrent spontaneous abortion

José Bellver; Sérgio Reis Soares; Claudio Álvarez; Elkin Muñoz; Alberto Ramírez; Carmen Rubio; Vicente Serra; J. Remohí; A. Pellicer


Human Reproduction | 2007

Implantation is apparently unaffected by the dopamine agonist Cabergoline when administered to prevent ovarian hyperstimulation syndrome in women undergoing assisted reproduction treatment: a pilot study

Claudio Álvarez; Isabel Alonso-Muriel; Gabriela García; Juana Crespo; José Bellver; Carlos Simón; A. Pellicer


Reproductive Biomedicine Online | 2009

Symposium: Update on prediction and management of OHSS. Prevention of OHSS--dopamine agonists.

Cristiano Busso; Juan A. Garcia-Velasco; Raúl Gómez; Claudio Álvarez; Carlos Simón; A. Pellicer


Reproductive Biomedicine Online | 2016

Strategies to manage refractory endometrium: state of the art in 2016

Juan A. Garcia-Velasco; Belen Acevedo; Claudio Álvarez; Monica Alvarez; José Bellver; Juan Fontes; J. Landeras; Dolors Manau; Francisca Martínez; Elkin Muñoz; Ana Robles; Luis Rodriguez-Tabernero


Fertility and Sterility | 2005

The singleton, term gestation, and live birth rate per cycle initiated: a 1-year experience in in vitro fertilization cycles with native and donated oocytes

José Bellver; Carmela Albert; Sérgio Reis Soares; Claudio Álvarez; Antonio Pellicer

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A. Pellicer

University of Valencia

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Francisca Martínez

Autonomous University of Barcelona

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J. Remohí

University of Valencia

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