Search results for "Ovulation"
showing 10 items of 127 documents
Polycystic ovary syndrome
2016
Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the p…
Acute stress may induce ovulation in women
2010
Abstract Background This study aims to gather information either supporting or rejecting the hypothesis that acute stress may induce ovulation in women. The formulation of this hypothesis is based on 2 facts: 1) estrogen-primed postmenopausal or ovariectomized women display an adrenal-progesterone-induced ovulatory-like luteinizing hormone (LH) surge in response to exogenous adrenocorticotropic hormone (ACTH) administration; and 2) women display multiple follicular waves during an interovulatory interval, and likely during pregnancy and lactation. Thus, acute stress may induce ovulation in women displaying appropriate serum levels of estradiol and one or more follicles large enough to respo…
Isotopic ordering in eggshells reflects body temperatures and suggests differing thermophysiology in two Cretaceous dinosaurs
2015
International audience; Our understanding of the evolutionary transitions leading to the modern endothermic state of birds and mammals is incomplete, partly because tools available to study the thermo-physiology of extinct vertebrates are limited. Here we show that clumped isotope analysis of eggshells can be used to determine body temperatures of females during periods of ovulation. Late Cretaceous titanosaurid eggshells yield temperatures similar to large modern endo-therms. In contrast, oviraptorid eggshells yield temperatures lower than most modern endotherms but B6 °C higher than co-occurring abiogenic carbonates, implying that this taxon did not have thermoregulation comparable to mod…
Ovulation-inducing activity of luliberin (LHRH) complexed by copper(II), nickel(II), and zinc(II) ions.
1990
We have shown that the complexation of luteinizing hormone releasing hormone, luliberin (LHRH), a hypothalamic neurohormone, by Cu(II), Ni(II), and Zn(II) may affect its basic, ovulation-inducing potency in the dose responsive manner. Some explanation of the obtained results are offered here.
Unpredicted ovulations and conceptions during early pregnancy: an explanatory mechanism of human superfetation
2012
In this bioessay, a literature review on human superfetation was performed in order to find epidemiological variables associated with this phenomenon. Thereafter, an explanatory mechanism of superfetation compatible with the endocrinological, histological and physiological changes undergone by women during early pregnancy is proposed. Superfetation can be defined as the ovulation, fertilisation and implantation of a second or additional embryo(s) during pregnancy. The literature review evidences a small discordance in gestational age between dizygotic twins in humans (range: 2–4 weeks; mean ± s.e.m.: 3.3 ± 0.3 weeks). This difference is compatible with a luteal out-of-phase (LOOP; i.e. atyp…
The Androgen Excess and PCOS Society criteria for the polycystic ovary syndrome: the complete task force report.
2009
Abstract OBJECTIVE: To review all available data and recommend a definition for polycystic ovary syndrome (PCOS) based on published peer-reviewed data, whether already in use or not, to guide clinical diagnosis and future research. DESIGN: Literature review and expert consensus. SETTING: Professional society. PATIENTS: None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): A systematic review of the published peer-reviewed medical literature, by querying MEDLINE databases, to identify studies evaluating the epidemiology or phenotypic aspects of PCOS. RESULT(S): The Task Force drafted the initial report, following a consensus process via electronic communication, which was then reviewed and c…
Influence of follicle rupture and uterine contractions on intrauterine insemination outcome: a new predictive model.
2014
Objective To correlate the detection of follicle rupture and the number of uterine contractions per minute with the outcome of IUI and to build a predictive model for the outcome of IUI including these parameters. Design Retrospective cohort study. Setting Fertility clinic. Patient(s) We analyzed data from 610 women who underwent homologous or donor double IUI from 2005 to 2010 and whose data of uterine contractions or follicle rupture were recorded. Intervention(s) None. Main Outcome Measure(s) Live-birth rate. Result(s) Nine hundred seventy-nine IUI cycles were included. The detection of follicle rupture (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.30–3.01) and the number of ut…
The type of GnRH analogue used during controlled ovarian stimulation influences early embryo developmental kinetics: a time-lapse study
2013
OBJECTIVE: To explore if the GnRH analogue used for controlled ovarian stimulation (COS) and the ovulation triggering factor (GnRH agonist + hCG triggering versus GnRH antagonist + GnRH agonist triggering) affect embryo development and kinetics.STUDY DESIGN: In a retrospective cohort study in the Instituto Valenciano de Infertilidad (IVI) Alicante and the Instituto Universitario-IVI Valencia, Spain, 2817 embryos deriving from 400 couples undergoing oocyte donation were analysed. After controlled ovarian stimulation and IVF/intracytoplamic sperm injection, the timing of embryonic cleavages was assessed by a video time-lapse system. The results were analysed using Student's t test for compari…
La objeción de conciencia farmacéutica a la píldora postcoital
2003
The article represents a taking of position regarding the matter of the conscience objection towards the morning-after pill (MAP). The MAP is considered like an emergency contraception that the woman can take within the 72 hours from the sexual intercourse. The mechanisms of action of the product can be the following: a. to avoid the ovulation; b. to prevent the fusion between oocyte and sperm after the ovulation; c. to make impossible the implant of the embryo in the uterus. The author questions in the article if the MAP is abortive and, in this case, explicits the fundamental points of the Spanish law about the conscience objection. It is not difficult to ascertain that the MAP acts as co…
Lifecycle of Polycystic Ovary Syndrome (PCOS): From In Utero to Menopause
2013
Context: Polycystic ovary syndrome (PCOS) is diagnosed during the reproductive years when women present with 2 of 3 of the following criteria: 1) irregular menstrual cycles or anovulation, 2) hyperandrogenism, and 3) PCO morphology. However, there is evidence that PCOS can be identified from early infancy to puberty based on predisposing environmental influences. There is also increasing information about the PCOS phenotype after menopause. The goal of this review is to summarize current knowledge about the appearance of PCOS at different life stages and the influence of reproductive maturation and senescence on the PCOS phenotype. Evidence: PubMed, the bibliography from the Evidence-Based …