Atualizações Científicas – 19 a 25 de março de 2012

Publicado em: 26 de Março de 2012

Na última semana, a comunidade científica publicou artigos sobre Infertilidade e Reprodução Humana. A Fecondare selecionou esses artigos e disponibiliza o resumo para que você se mantenha atualizado.

Circulating luteinizing hormone level after triggering oocyte maturation with GnRH agonist may predict oocyte yield in flexible GnRH antagonist protocol

Publicado em 14 de março de 12 pela Human Reproduction, disponível no Oxford Journal.

Resumo:

BACKGROUND: The use of gonadotrophin-releasing hormone (GnRH) agonist for triggering final oocyte maturation and ovulation can reduce ovarian hyperstimulation syndrome (OHSS) in high-risk patients. LH levels post-trigger with GnRH agonist might be correlated with oocyte yield and maturity. Our aim was to evaluate the relationship between serum LH level at 12-h post-trigger and oocyte yield, maturity and fertilization rate in patients at high risk of OHSS and therefore who were treated with a flexible GnRH antagonist protocol in which final oocyte maturation was triggered with GnRH agonist.

METHODS: In a prospective cohort study, 91 patients at high risk of OHSS were treated with a flexible GnRH antagonist protocol and divided into six groups according to their serum LH levels at 12-h after GnRH agonist administration: ≤15.0, 15.1-30.0, 30.1-45.0, 45.1-60.0, 60.1-75.0 and >75.0 IU/l. The oocyte yield, maturity, fertilization rate and clinical outcomes for each LH interval were analyzed.

RESULTS: There was a statistically significant reduction in oocyte yield with a concentration of serum LH ≤15.0 IU/l (P < 0.05), whereas no statistically significant differences in the oocyte maturity and fertilization rate among the six groups (P > 0.05) were seen. Only 5 out of 91 patients (5.5%) had a serum LH ≤15.0 IU/l at 12-h post-trigger with GnRH agonist. In addition, no statistically significant difference was seen regarding high-quality embryos, implantation rate, clinical pregnancy rate and early miscarriage between patients with LH ≤15.0 IU/l and >15.0 IU/l (P > 0.05).

CONCLUSIONS: Serum LH level at 12-h post-trigger with GnRHa

Matrix metalloproteinases and their tissue inhibitors in hypertension-related pregnancy complications

Publicado em 15 de março pela Journal of Human Hypertension, disponível no Pub Med.

Resumo: Matrix metalloproteinases (MMPs) are a family of endopeptidases that degrade the components of the extracellular matrix (ECM) such as collagen, and thus contribute to the remodelling and the physiological homeostasis of the ECM and its blood supply. The activities of these enzymes are regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and it has been suggested that a balance between MMPs and TIMPs plays an important role in vascular remodelling, angiogenesis and vasodilatation in a number of physiological situations. It follows that, regarding a relationship between MMPs and TIMPs, an imbalance between these molecules may lead to pathology in a wide range of conditions, including hypertension, cancer and pulmonary disease, and in the pathophysiology of reproduction. Indeed, regarding the latter, abnormalities in the maternal peripheral vasculature have been proposed as being (partly) responsible for the effects of hypertension on pregnancy and the development of complications including pre-eclampsia and eclampsia. However, the associations between MMPs, TIMPs and disease may be simply of association, not of pathology. This brief review explores current literature on the role of abnormalities of the ECM in general, focusing on the pathogenesis of hypertension and its complications during pregnancy as a model of disordered angiogenesis and remodelling. Journal of Human Hypertension advance online publication, 15 March 2012; doi:10.1038/jhh.2012.8

Favorable infertility outcomes following anti-tubercular treatment prescribed on the sole basis of a positive polymerase chain reaction test for endometrial tuberculosis

Publicado em 14 de março pela Hum. Reprod. Advance Acces, disponível no Oxfor Journal.

Resumo:

BACKGROUND: The endometrial tuberculosis (TB) PCR test is now commonly employed for the diagnosis of female genital TB, a common cause of infertility in India. Although treatment in the absence of demonstrable tubal damage may be of doubtful benefit to fertility, the presence of mycobacterial DNA demonstrated by a positive PCR indicates infection by tubercle bacilli causing sub-clinical or latent disease potentially responsible for future clinical manifestations. This study was undertaken to assess the outcome of infertility management following early anti-tubercular treatment (ATT) based only on a positive endometrial TB-PCR test.

METHODS: This was an intervention study conducted at an IVF center in northern India in 443 infertile women of whom 169 (38.15%) were found to have positive TB-PCR (Group I), while 274 (61.85%) had negative Mycobacterium tuberculosis (MTB)-PCR (Group II).

RESULTS There were no statistical differences in the two groups in the overall pregnancy rate, 101 (59.8%) versus 167 (60.9%). In Group I, 48 (92.3%) spontaneous conceptions occurred within the first 12 months, i.e. during the period of ATT administration or within 6 months of treatment completion; in Group II, the occurrence of spontaneous conceptions was distributed more evenly in relation to time, i.e. 36 (53.7%) in <12 months as compared with 31 (46.3%) after first year (P< 0.001).

CONCLUSION Infertile women without tubal or endometrial damage given early anti-tuberculosis treatment based on a positive endometrial TB-PCR test had an excellent chance of early spontaneous conception.

Infertile women of Time-lapse monitoring as a tool for clinical embryo assessment.

Publicado em 14 de março de 2012 pela Human Reproduction, disponível no Oxford Journal.

Resumo: As elective transfer of a single embryo (eSET) becomes increasingly accepted, the need to improve implantation rates becomes crucial. Selecting the most competent embryo therefore constitutes a major challenge in assisted reproductive technology. Embryo morphology and developmental stage at given time points are closely correlated with developmental competence and assessment of morphological parameters at discrete inspection points thus remains the preferred way of evaluating embryonic potential. Lately, more attention has been given to the assessment of dynamic embryo development as a tool for evaluating embryonic potential. The introduction of time-lapse equipment approved for use on human embryos offers novel clinical opportunities for continuous monitoring of embryos, enabling flexible evaluation of known morphological parameters and potentially introducing new dynamic markers of viability. Due to lack of larger, randomized clinical studies it remains to be elucidated whether embryo selection using dynamic parameters improves clinical outcome and which parameters are of significance. Before such randomized controlled studies are organized, the most promising parameters to evaluate must be identified. This mini-review summarizes the current knowledge about dynamic markers of viability and discusses the potential clinical role of time-lapse analysis in embryo assessment and selection.

Ion Channels in Sperm Physiology, Male Fertility and Infertility

Publicado em 22 de março de 12 pelo J Androl, disponível no Pub Med.

Resumo: Ion channels regulate the membrane potential and intracellular ionic concentration and thus serve a central role in various cellular processes. Several ion channels have been identified in the germ cells including sperm, emphasizing their importance in male fertility and reproduction. The molecular mechanism of ion transport and the nature of ion channels involved have begun to emerge only recently despite the fact that several ligand and voltage gated channels had been identified and localized on sperm. The presence of catsper gene family channels (CatSpers 1-4), proton voltage gated ion channel (Hv1), potassium voltage gated ion channel (SLO3/KCNU1), sodium voltage gated channel (Nav 1.1-1.9) and the members of transient receptor potential (TRP) channel family suggest indispensable role of ion channels in sperm physiology and fertility potential. Ion channels are the key players in very important processes such as capacitation and acrosome reaction which are critical steps in sperm physiology preparing it for fertilization. For example, CatSpers, Hv1, Slo3, TRPC family members have been proposed to participate in acrosome reaction, thereby making them most important for sperm fertility. Similarly, Nav channels could play a crucial role in the non-capacitated sperm and in the initial capacitation steps. The role of ion channels seems indispensable for sperm fertility as evident from studies on animal models; however, the functional defects in infertilehuman males await further exploration. The present article brings an update on the role of ion channels in sperm physiology, male fertility and infertility.

The impact in older women of ovarian FMR1 genotypes and sub-genotypes on ovarian reserve.

Publicado em 16 de março de 2012 pela PLoS One, disponível no PubMed.

Resumo: We recently associated ovarian FMR1genotypes and sub-genotypes with distinct ovarian aging patterns. How they impact older females is, however, unknown. We, therefore, investigated 217 consecutive first in vitro fertilization (IVF) cycles in women >40 assessing oocyte yields, stratified for better (anti-Müllerian hormone, AMH >1.05 ng/mL) or poorer (AMH≤1.05 ng/mL) functional reserve (FOR)). Mean age was 42.4±2.0 years, mean AMH 0.76±0.92 ng/mL and mean oocyte yield 5.3±5.4. Overall, and in women with better FOR, FMR1 did not affect oocyte yields. With poorer FOR (AMH≤1.05 ng/mL) women with het-norm/high, however, demonstrated higher oocyte yields (5.0±3.8) than those with het-norm/low sub-genotype 3.1±2.5; P = 0.03), confirmed after log conversion. Known associated with low FOR at young age, het-norm/high, thus, appears to preserve FOR into older age, and both het sub-genotypes appear to expand female reproductive lifespan into opposite directions.

Conteúdo atualizado em: 17 de Abril de 2014

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