Embarazo múltiple posterior a la transferencia de embrión único: serie de casos y revisión de la literatura / Multiple pregnancies after single embryo transfer: case report and literature review

El embarazo gemelar es la complicación más frecuente tras técnicas de reproducción asistida (TRA). En un esfuerzo por disminuir su incidencia, cada vez más centros adoptan la medida de transferencia de embrión único. Sin embargo, a pesar de estas medidas, se ha observado que existe un riesgo elevado de duplicación embrionaria inherente a las TRA cuyo mecanismo permanece desconocido. En el presente trabajo presentamos una serie de casos y una revisión de la literatura acerca de los posibles mecanismos y teorías involucradas en dichos acontecimientos (AU)

Twin pregnancy is the most frequent complication for the assisted reproduction techniques. A strategy for reducing its incidence, many IVF centres have adopted a policy of single embryo transfer. However, despite these efforts, a risk of multiple pregnancies is still present and the mechanisms for its occurrence are unknown. We present a number of cases and a literature review discussing the theories and possible mechanisms involved (AU)

Regulación de la actividad GnRH. Los sistemas Kisspeptina/GPR54 y GnIH/GPR147 / GnRH activity regulation. Kisspeptin/GPR54 and GnIH/GPR147 systems

OBJETIVO: Revisar y actualizar la fisiología de la regulación de fertilidad y reproducción, poniendo especial énfasis en los factores neuroendocrinos que controlan la secreción pulsátil de GnRH. MATERIAL Y MÉTODOS: Revisión bibliográfica, utilizando como palabras clave «GnRH», «Kisspeptin», «GnIH», «RF-amide» y RPRF-3, entre otras. RESULTADOS: Siendo la secreción pulsátil de GnRH el elemento clave para el control de la secreción de gonadotrofinas, se describen los mecanismos neuroendocrinos (Kisspeptina, GnIH) que regulan la actividad de las neuronas GnRH

OBJECTIVE: To Review and update the physiology regulating fertility and reproduction, with particular emphasis on neuroendocrine factors controlling the pulsatile secretion of GnRH. MATERIAL AND METHODS: Review of the literature, using as key words «GnRH», «Kisspeptin», «GnIH», «RF-amide» and RPRF-3, among others. RESULTS: Being the pulsatile secretion of GnRH the key element for the control of gonadotrophin secretion, the neuroendocrine mechanisms (Kisspeptine, GnIH) that regulate the activity of GnRH neurons are described

[Proteomics and PCOS: Is it here the missing link? Literature review]. / Proteómica y síndrome de ovario poliquístico: ¿encontraremos aquí el eslabón perdido? Revisión de la bibliografía.

Polycystic ovary syndrome (PCOS) is known as a common gynecologic and endocrinology disease with multiple short and long-term consequences. It is one of the most common causes for hyperandrogenism and anovulation, increases the risk for metabolic syndrome, type 2 diabetes and cardiovascular disease. Its etiology remains unclear. PCOS is thought to be the result of the interaction between predisposing genetic variants with environmental factors and strongly depends on ethnicity. Proteomics allows the study of several hundreds or thousands of proteins in order to reveal physiological state of a tissue or an organ at the molecular level and to identify disease-specific biomarkers. Its use on PCOS patients will permit us to identify molecules that are involved in the PCOS pathology so we can develop specific diagnostic and management approaches.

[Polycystic ovary syndrome: is there a rise in the prevalence?]. / Síndrome de ovario poliquístico: Ha aumentado su prevalencia?

OBJECTIVE: To determine the prevalence of polycystic ovary syndrome (PCOS) according to the three major diagnostic criteria previously described in an unselected group of women from Spain and to identify the most common phenotypes of the disease. MATERIAL AND METHOD: An observational, transversal prevalence study was carried out between July 1 2014 and October 31 2014. All participants received a questionnaire and underwent a physical and trans-vaginal ultrasound examination. Blood samples were also collected for analysis of metabolic markers and hormones. PCOS was diagnosed according to three major criteria: NIH, Rotterdam and AE-PCOS criteria. Following diagnosis women with PCOS were assigned to one of four phenotypes. RESULTS: A total of 242 women were involved in the study. The prevalence for each major criteria was as follows: National Institute of Health (NIH) criteria had a prevalence of 1 4.88%, Rotterdam criteria had a prevalence of 29.34% and Androgen Excess and PCOS Society criteria presented a prevalence of 17.36%. The prevalence for each phenotype was: A, 40.85%; B, 25.35%; C, 8.45%; and D, 25.35%. PCOS women had more prevalence of hirsutism (36.61 %), infertility (25.35%), obesity (21.1 2%) and metabolic syndrome (11 .26%) than controls (7.01%, 6.43%, 5.84% and 2.33% respectively). CONCLUSION: There is a rise in the prevalence of PCOS in Caucasian population with the classic phenotype (oligo-anovulation, hyperandrogenism, polycystic ovaries) being the most common presentation of the syndrome.

[Influence of the high peak serum estradiol on the outcome of in vitro fertilization cycles]. / Influencia de las concentraciones séricas de estradiol en el resultado de ciclos de reproducción asistida in vitro.

BACKGROUND: For the use of assisted reproductive technologies of high complexity (IVF-ET and ICSI) is essential to proper ovarian stimulation with recombinant FSH drugs menotropins, as well as the use of GnRH analogues. OBJECTIVE: To correlate serum estradiol level on day 10th with the outcome of in vitro fertilization cycles. MATERIAL AND METHOD: Retrospective study of 523 IVF cycles, selected and analyzed from 2005 to 2009. Patients underwent individualized stimulation protocols with gonadotropins and agonist (late luteal phase). The patients were divided into three groups according with the serum level of estradiol on day 10th of stimulation: Group I, patients with serum level of Estradiol below 1,000 pg/mL; Group II, with levels between 1,000-4,000 pg/mL; and Group III, with levels above 4,000 pg/mL. Peak serum estradiol levels, oocyte number, fertilization rates, implantation rates, and pregnancy rates were compared among groups. RESULTS: The fertilization rate was 62.8 in Group I; 60.6% in Group II, and 54.2% in Group III. The pregnancy rate in Group I was 29.8%; in Group II, 37.3%; and 24% for Group III. The implantation rates were 14, 22 and 14% for each group respectively (I, II and III). CONCLUSIONS: There is an inverse relationship between high peak serum estradiol levels and pregnancy rate; the implantation rate seems affected by the extreme levels of serum estradiol. The percent of total mature oocytes and fertilization rate improve with serum levels of estradiol at physiologic values.