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Scientific Reports Nov 2022Pre-labour uterine contractions, occurring throughout pregnancy, are an important phenomenon involving the placenta in addition to the myometrium. They alter the uterine...
Pre-labour uterine contractions, occurring throughout pregnancy, are an important phenomenon involving the placenta in addition to the myometrium. They alter the uterine environment and thus potentially the blood supply to the fetus and may thus provide crucial insights into the processes of labour. Assessment in-vivo is however restricted due to their unpredictability and the inaccessible nature of the utero-placental compartment. While clinical cardiotocography (CTG) only allows global, pressure-based assessment, functional magnetic resonance imaging (MRI) provides an opportunity to study contractile activity and its effects on the placenta and the fetus in-vivo. This study aims to provide both descriptive and quantitative structural and functional MR assessments of pre-labour contractions in the human uterus. A total of 226 MRI scans (18-41 weeks gestation) from ongoing research studies were analysed, focusing on free-breathing dynamic quantitative whole uterus dynamic T2* maps. These provide an indirect measure of tissue properties such as oxygenation. 22 contractile events were noted visually and both descriptive and quantitative analysis of the myometrial and placental changes including volumetric and T2* variations were undertaken. Processing and analysis was successfully performed, qualitative analysis shows distinct and highly dynamic contraction related characteristics including; alterations in the thickness of the low T2* in the placental bed and other myometrial areas, high intensity vessel-like structures in the myometrium, low-intensity vessel structures within the placental parenchyma and close to the chorionic plate. Quantitative evaluation shows a significant negative correlation between T2* in both contractile and not-contractile regions with gestational age (p < 0.05) as well as a significant reduction in T2* during contractions. The T2* values in the myometrium were however not correlated to gestational age (p > 0.5). The quantitative and qualitative description of uterine pre-labour contractions including dynamic changes and key characteristics aims to contribute to the sparsely available in-vivo information and to provide an in-vivo tool to study this important phenomenon. Further work is required to analyse the origins of these subclinical contractions, their effects in high-risk pregnancies and their ability to determine the likelihood of a successful labour. Assessing T2* distribution as a marker for placental oxygenation could thus potentially complement clinically used cardiotocography measurements in the future.
Topics: Female; Pregnancy; Humans; Myometrium; Placenta; Uterine Contraction; Labor, Obstetric; Uterus
PubMed: 36329074
DOI: 10.1038/s41598-022-22008-3 -
Gynecological Endocrinology : the... Jul 2021Adenomyosis is a benign uterine disorder characterized by the invasion of the endometrium within the myometrium, starting from the junctional zone (JZ), the inner... (Review)
Review
OBJECTIVE
Adenomyosis is a benign uterine disorder characterized by the invasion of the endometrium within the myometrium, starting from the junctional zone (JZ), the inner hormone dependent layer of the myometrium that plays an important role in sperm transport, implantation and placentation. The resulting histological abnormalities and functional defects may represent the pathogenic substrate for infertility and pregnancy complications. The objective of this paper is to review the literature to evaluate the correlation between inner myometrium alterations and infertility and to assess the role of JZ in the origin of adverse obstetric outcomes of both spontaneous and fertilization (IVF) pregnancies.
METHODS
we searched Pubmed for all original and review articles in the English language from January1962 until December 2019, using the MeSH terms of 'adenomyosis', 'junctional zone', combined with 'infertility', 'obstetrical outcomes', 'spontaneous conception', ' fertilization' and 'classification'. The review was divided into three sections to assess this pathogenic correlation, evaluating also the importance of classification of the disease.
RESULTS AND CONCLUSIONS
Absent or incomplete remodeling of the JZ can affect uterine peristalsis, alter vascular plasticity of the spiral arteries and activate inflammatory pathways, all related to adverse obstetric outcomes. Despite these observations, there is still limited evidence whether adenomyosis is a cause of infertility. However, it is reasonable to screen patients for adenomyosis, to consider pregnant women with diffuse adenomyosis at high risk of adverse obstetric outcomes, and to evaluate the importance of a noninvasive validated classification in the management of women with adenomyosis.
Topics: Adenomyosis; Endometrium; Female; Fertilization in Vitro; Humans; Imaging, Three-Dimensional; Infertility, Female; Magnetic Resonance Imaging; Myometrium; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Risk Assessment; Ultrasonography; Ultrasonography, Prenatal
PubMed: 33587014
DOI: 10.1080/09513590.2021.1878131 -
Women's Health (London, England) Aug 2015Several lines of recent evidence suggest that pelvic innervation is altered in endometriosis-affected women, and there is a strong presumption that nerve fibers... (Review)
Review
Several lines of recent evidence suggest that pelvic innervation is altered in endometriosis-affected women, and there is a strong presumption that nerve fibers demonstrated in eutopic endometrium (of women with endometriosis) and in endometriotic lesions play roles in the generation of chronic pelvic pain. The recent observation of sensory C, sensory A-delta, sympathetic and parasympathetic nerve fibers in the functional layer of endometrium of most women affected by endometriosis, but not demonstrated in most women who do not have endometriosis, was a surprise. Nerve fiber densities were also greatly increased in myometrium of women with endometriosis and in endometriotic lesions compared with normal peritoneum. Chronic pelvic pain is complex, and endometriosis is only one condition which contributes to this pain. The relationship between the presence of certain nerve fibers and the potential for local pain generation requires much future research. This paper reviews current knowledge concerning nerve fibers in endometrium, myometrium and endometriotic lesions, and discusses avenues of research that may improve our knowledge and lead to enriched understanding and management of endometriotic pain symptoms.
Topics: Adult; Endometriosis; Endometrium; Female; Humans; Myometrium; Nerve Fibers; Pelvic Pain; Women's Health
PubMed: 26314611
DOI: 10.2217/whe.15.47 -
Fertility and Sterility Jan 2024
Topics: Humans; Female; Myometrium
PubMed: 37979609
DOI: 10.1016/j.fertnstert.2023.11.016 -
Fertility and Sterility Mar 2023
Topics: Female; Humans; Adenomyosis; Ultrasonography; Myometrium
PubMed: 36621709
DOI: 10.1016/j.fertnstert.2022.12.043 -
Ultrasound in Obstetrics & Gynecology :... Nov 2023Two-dimensional (2D) transvaginal ultrasound (TVS) is an accessible and cost-effective diagnostic tool for the detection of adenomyosis. Different ultrasound features...
OBJECTIVE
Two-dimensional (2D) transvaginal ultrasound (TVS) is an accessible and cost-effective diagnostic tool for the detection of adenomyosis. Different ultrasound features related to adenomyosis have been described, but the predictive value of each ultrasound sign and their combinations requires further investigation. We aimed to analyze the accuracy of 2D-TVS and describe possible combinations of ultrasound signs with a high predictive value in the diagnosis of adenomyosis.
METHODS
This was a prospective multicenter study of patients scheduled for laparoscopic hysterectomy who had been examined using standardized 2D-TVS at nine expert centers specializing in the diagnosis and treatment of endometriosis. 2D-TVS examination included nine typical adenomyosis ultrasound features, comprising heterogeneous myometrium, myometrial linear striations, myometrial cysts, subendometrial microcysts, asymmetrical myometrial thickening, uterine enlargement, the 'question mark sign', thickening of the junctional zone and hyperechoic myometrial spots, in order to predict or exclude the presence of adenomyosis. Ultrasound examination results were compared with histology after hysterectomy. The diagnostic reliability of the nine ultrasound signs and their combinations, and the influence of concurrent fibroids on the accuracy of the results, were analyzed.
RESULTS
A total of 202 patients were enrolled into the study. Histopathological examination revealed adenomyosis in 130 patients (64.4%). The accuracy of prediction of adenomyosis by 2D-TVS examination using all signs was 63.4% (positive predictive value, 71.5%; negative predictive value, 48.6%; sensitivity, 71.5%; specificity, 48.6%). Heterogeneous myometrium, myometrial cysts, subendometrial microcysts and hyperechoic myometrial spots showed the highest accuracy (55.7-62.1%) as individual ultrasound signs for the prediction of adenomyosis. The combination of the most accurate ultrasound signs (subendometrial microcysts, myometrial cysts and heterogeneous myometrium) improved the specificity of prediction (86.1%) when compared with that of these three single markers (35.2-81.7%). Uterine enlargement and asymmetry showed both low sensitivity (60.8% and 52.3%, respectively) and specificity (41.7% and 49.3%, respectively) as individual sonographic signs.
CONCLUSIONS
Heterogeneous myometrium, myometrial cysts, subendometrial microcysts and hyperechoic myometrial spots showed the highest accuracy for the detection of adenomyosis in this study, while uterine enlargement and asymmetry led to high false-positive and false-negative results. A combination of ultrasound features including the most accurate signs increases specificity. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Female; Humans; Adenomyosis; Cysts; Endometriosis; Myometrium; Prospective Studies; Reproducibility of Results; Sensitivity and Specificity; Ultrasonography
PubMed: 36920431
DOI: 10.1002/uog.26197 -
Biology of Reproduction Dec 2014Tissue-specific (or somatic) stem cells constitute a subset of cells residing in normal adult tissues. By undergoing asymmetric division, they retain their ability to... (Review)
Review
Tissue-specific (or somatic) stem cells constitute a subset of cells residing in normal adult tissues. By undergoing asymmetric division, they retain their ability to self-renew while producing daughter cells that go on to differentiate and play a role in tissue regeneration and repair. The human uterus consists primarily of endometrium and myometrium (the smooth muscle layer) that rapidly enlarges through its tremendous regenerative and remodeling capacity to accommodate the developing fetus. Such uterine enlargement and remodeling can take place repeatedly and cyclically over the course of a woman's reproductive life. These unique properties of the uterus suggest the existence of endometrial and myometrial stem cell systems. In addition, like somatic cells, tumor stem cells or tumor-initiating cells, a subset of cells within a tumor, retain the ability to reconstitute tumors. Uterine smooth muscle cells are thought to be the origin of leiomyomas that are the most common type of gynecologic tumor. Recent work has identified, isolated, and characterized putative stem/progenitor cells in the myometrium and in leiomyomas. Here, we review current studies of myometrial and leiomyoma stem/progenitor cells and provide a new paradigm for understanding myometrial physiology and pathology and how these cells might contribute to uterine remodeling during pregnancy and the formation of leiomyomas. The role of the WNT/CTNNB1 pathway in the pathogenesis of leiomyoma is also discussed.
Topics: Adult; Animals; Disease Models, Animal; Female; Humans; Leiomyoma; Myometrium; Neoplastic Stem Cells; Organ Specificity; Pregnancy; Stem Cells; Uterine Neoplasms
PubMed: 25376230
DOI: 10.1095/biolreprod.114.123794 -
Best Practice & Research. Clinical... Oct 2018The laboring uterus is generally thought to initiate contractions much similar to the heart, with a single, dedicated pacemaker. Research on human and animal models over... (Review)
Review
The laboring uterus is generally thought to initiate contractions much similar to the heart, with a single, dedicated pacemaker. Research on human and animal models over decades has failed to identify such pacemaker. On the contrary, data indicate that instead of being fixed at a site similar to the sinoatrial node of the heart, the initiation site for each uterine contraction changes during time, often with each contraction. The enigmatic uterine "pacemaker" does not seem to fit the standard definition of what a pacemaker should be. The uterine pacemaker must also mesh with the primary physiological function of the uterus - to generate intrauterine pressure. This requires that most areas of the uterine wall contract in a coordinated, or synchronized, manner for each contraction of labor. It is not clear whether the primary mechanism of the uterine pacemaker is a slow-wave generator or an impulse generator. Slow waves in the gut initiate localized smooth muscle contractions. Because the uterus and the gut have somewhat similar cellular and tissue structure, it is reasonable to consider if uterine contractions are paced by a similar mechanism. Unfortunately, there is no convincing experimental verification of uterine slow waves. Similarly, there is no convincing evidence of a cellular mechanism for impulse generation. The uterus appears to have multiple widely dispersed mechanically sensitive functional pacemakers. It is possible that the coordination of organ-level function occurs through intrauterine pressure, thus creating wall stress followed by activation of many mechanosensitive electrogenic pacemakers.
Topics: Biological Clocks; Electromyography; Female; Humans; Labor, Obstetric; Myometrium; Pregnancy; Uterine Contraction; Uterus
PubMed: 29866432
DOI: 10.1016/j.bpobgyn.2018.04.002 -
Advances in Anatomy, Embryology, and... 2017The small heat shock protein B (HSPB) family is comprised of eleven members with many being induced by physiological stressors. In addition to being molecular... (Review)
Review
The small heat shock protein B (HSPB) family is comprised of eleven members with many being induced by physiological stressors. In addition to being molecular chaperones, it is clear these proteins also play important roles in cell death regulation, cytoskeletal rearrangements, and immune system activation. These processes are important for the uterine smooth muscle or myometrium during pregnancy as it changes from a quiescent tissue, during the majority of pregnancy, to a powerful and contractile tissue at labor. The initiation and progression of labor within the myometrium also appears to require an inflammatory response as it is infiltrated by immune cells and it produces pro-inflammatory mediators. This chapter summarizes current knowledge on the expression of HSPB family members in the myometrium during pregnancy and speculates on the possible roles of these proteins during myometrial programming and transformation of the myometrium into a possible immune regulatory tissue.
Topics: Animals; Female; Heat-Shock Proteins, Small; Humans; Muscle, Smooth; Myometrium; Pregnancy; Uterine Contraction; Uterus
PubMed: 28389752
DOI: 10.1007/978-3-319-51409-3_5 -
Journal of Minimally Invasive Gynecology Feb 2022To evaluate the ultrasound features, types, and degrees of adenomyosis among adolescents and to correlate these findings with clinical symptoms DESIGN: A retrospective... (Observational Study)
Observational Study
STUDY OBJECTIVE
To evaluate the ultrasound features, types, and degrees of adenomyosis among adolescents and to correlate these findings with clinical symptoms DESIGN: A retrospective observational study.
SETTING
Gynecological ultrasound units from January 2014 to June 2020.
PATIENTS
A total of 43 adolescents (aged 12-20 years) who were diagnosed as having adenomyosis at a pelvic ultrasound examination.
INTERVENTIONS
Ultrasound features and location and type of adenomyosis within the uterus were evaluated on stored 2-dimensional images and videos and 3-dimensional volumes. Adenomyosis was classified as mild, moderate, and severe according to the extension of the disease in the uterus as described in our previous published classification.
MEASUREMENTS AND MAIN RESULTS
Adenomyotic features recorded among our population were myometrial hyperechoic areas, uterine wall asymmetry, intramyometrial cystic areas, and some types of junctional zone alterations. The posterior uterine wall (58%) and the outer myometrial layer (93%) were mostly affected. In 44% of adolescents (19/43) with adenomyosis, at least 1 location of pelvic endometriosis was documented. Dysmenorrhea was the most commonly reported symptoms (88%), and it was associated with adenomyosis of the outer myometrium, myometrial hyperechoic areas, uterine wall asymmetry, and intramyometrial cystic areas. Adolescents with dyspareunia showed diffuse adenomyosis (9/9 patients) including both the inner and outer myometrium (7/9 patients) and in the posterior wall (7/9 patients). Heavy menstrual bleeding was associated with diffuse adenomyosis (18/23 patients) mostly of the outer myometrium (22/23 patients). Scoring system showed predominantly mild disease and no severe adenomyosis was found. Adolescents with diffuse adenomyosis were significantly older and showed a high percentage of heavy menstrual bleeding compared with those with the focal disease of the inner myometrium.
CONCLUSION
This study shows that adenomyosis is not only a pathology of adult life, but it involves young patients mostly in a mild-to-moderate form and is associated with typical painful symptoms. In adolescents, the diagnosis of adenomyosis is feasible through a noninvasive way with ultrasound and a proper management can be set.
Topics: Adenomyosis; Adolescent; Adult; Child; Dysmenorrhea; Endometriosis; Female; Humans; Myometrium; Ultrasonography; Uterus; Young Adult
PubMed: 34464760
DOI: 10.1016/j.jmig.2021.08.023