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May RW, Maso Talou GD, Clark AR, Mynard JP, Smolich JJ, Blanco PJ, Müller LO, Gentles TL, Bloomfield FH, Safaei S. From fetus to neonate: A review of cardiovascular modeling in early life. WIREs Mech Dis 2023:e1608. [DOI: 10.1002/wsbm.1608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 01/31/2023] [Accepted: 03/03/2023] [Indexed: 04/03/2023]
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Saw SN, Dai Y, Yap CH. A Review of Biomechanics Analysis of the Umbilical-Placenta System With Regards to Diseases. Front Physiol 2021; 12:587635. [PMID: 34475826 PMCID: PMC8406807 DOI: 10.3389/fphys.2021.587635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Abstract
Placenta is an important organ that is crucial for both fetal and maternal health. Abnormalities of the placenta, such as during intrauterine growth restriction (IUGR) and pre-eclampsia (PE) are common, and an improved understanding of these diseases is needed to improve medical care. Biomechanics analysis of the placenta is an under-explored area of investigation, which has demonstrated usefulness in contributing to our understanding of the placenta physiology. In this review, we introduce fundamental biomechanics concepts and discuss the findings of biomechanical analysis of the placenta and umbilical cord, including both tissue biomechanics and biofluid mechanics. The biomechanics of placenta ultrasound elastography and its potential in improving clinical detection of placenta diseases are also discussed. Finally, potential future work is listed.
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Affiliation(s)
- Shier Nee Saw
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Yichen Dai
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Choon Hwai Yap
- Department of Bioengineering, Imperial College London, London, United Kingdom
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Abstract
PURPOSE OF REVIEW There is an increasing recognition that structural abnormalities and functional changes in the placenta can have deleterious effects on the development of the fetal heart. This article reviews the role of the placenta and the potential impact of placental insufficiency on fetuses with congenital heart disease. RECENT FINDINGS The fetal heart and the placenta are directly linked because they develop concurrently with shared regulatory and signaling pathways. Placental disease is more common in pregnancies carrying a fetus with congenital heart disease and the fetal response to placental insufficiency may lead to the postnatal persistence of cardiac remodeling. The mechanisms underlying this placental-fetal axis of interaction potentially include genetic factors, oxidative stress, chronic hypoxia, and/or angiogenic imbalance. SUMMARY The maternal-placental-fetal circulation is critical to advancing our understanding of congenital heart disease. We must first expand our ability to detect, image, and quantify placental insufficiency and dysfunction in utero. Elucidating the modifiable factors involved in these pathways is an exciting opportunity for future research, which may enable us to improve outcomes in patients with congenital heart disease.
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Affiliation(s)
- Jordan A Cohen
- University of Miami, Miller School of Medicine, Miami, Florida
| | - Jack Rychik
- Department of Pediatrics, Division of Cardiology, Children's Hospital of Philadelphia
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jill J Savla
- Department of Pediatrics, Division of Cardiology, Children's Hospital of Philadelphia
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Abstract
The placenta is a multi-functional organ that exchanges blood gases and nutrients between a mother and her developing fetus. In humans, fetal blood flows through intricate networks of vessels confined within villous trees, the branches of which are bathed in pools of maternal blood. Fluid mechanics and transport processes play a central role in understanding how these elaborate structures contribute to the function of the placenta, and how their disorganization may lead to disease. Recent advances in imaging and computation have spurred significant advances in simulations of fetal and maternal flows within the placenta, across a range of lengthscales. Models describe jets of maternal blood emerging from spiral arteries into a disordered and deformable porous medium, and solute uptake by fetal blood flowing through elaborate three-dimensional capillary networks. We survey recent developments and emerging challenges in modeling flow and transport in this complex organ.
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Affiliation(s)
| | - Igor L. Chernyavsky
- School of Mathematics, University of Manchester, UK
- Maternal and Fetal Health Research Centre, Division of Developmental
Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine
& Health, University of Manchester, UK
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5
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Abstract
Pregnancy complications are a major clinical concern due to the related maternal and fetal morbidity. Many are caused through defective placentation, but research into placental function is difficult, principally because of the ethical limitations associated with the in-vivo organ and the difficulty of extrapolating animal models. Perfused by two separate circulations, the maternal and fetal bloodstreams, the placenta has a unique structure and performs multiple complex functions. Three-dimensional imaging and computational modelling are becoming popular tools to investigate the morphology and physiology of this organ. These techniques bear the potential for better understanding the aetiology and development of placental pathologies, however, their full potential is yet to be exploited. This review aims to summarize the recent insights into placental structure and function by employing these novel techniques.
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Abstract
The placenta is the largest fetal organ, and toward the end of pregnancy the umbilical circulation receives at least 40% of the biventricular cardiac output. It is not surprising, therefore, that there are likely to be close haemodynamic links between the development of the placenta and the fetal heart. Development of the placenta is precocious, and in advance of that of the fetus. The placenta undergoes considerable remodeling at the end of the first trimester of pregnancy, and its vasculature is capable of adapting to environmental conditions and to variations in the blood supply received from the mother. There are two components to the placental membranes to consider, the secondary yolk sac and the chorioallantoic placenta. The yolk sac is the first of the extraembryonic membranes to be vascularized, and condensations in the mesenchyme at ~17 days post-conception (p.c.) give rise to endothelial and erythroid precursors. A network of blood vessels is established ~24 days p.c., with the vitelline vein draining through the region of the developing liver into the sinus venosus. Gestational sacs of early pregnancy failures often display aberrant development of the yolk sac, which is likely to be secondary to abnormal fetal development. Vasculogenesis occurs in the villous mesenchyme of the chorioallantoic placenta at a similarly early stage. Nucleated erythrocytes occupy the lumens of the placental capillaries and end-diastolic flow is absent in the umbilical arterial circulation throughout most of the first trimester, indicating a high resistance to blood flow. Resistance begins to fall in the umbilico-placental circulation around 12–14 weeks. During normal early pregnancy the placental capillary network is plastic, and considerable remodeling occurs in response to the local oxygen concentration, and in particular to oxidative stress. In pregnancies complicated by preeclampsia and/or fetal growth restriction, utero-placental malperfusion induces smooth muscle cells surrounding the placental arteries to dedifferentiate and adopt a proliferative phenotype. This change is associated with increased umbilical resistance measured by Doppler ultrasound, and is likely to exert a major effect on the developing heart through the afterload. Thus, both the umbilical and maternal placental circulations may impact on development of the heart.
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Affiliation(s)
- Graham J Burton
- Department of Physiology, Development and Neuroscience, Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom
| | - Eric Jauniaux
- Faculty of Population Health Sciences, EGA Institute for Women's Health, University College London, London, United Kingdom
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Abstract
Epidemiological evidence links an individual's susceptibility to chronic disease in adult life to events during their intrauterine phase of development. Biologically this should not be unexpected, for organ systems are at their most plastic when progenitor cells are proliferating and differentiating. Influences operating at this time can permanently affect their structure and functional capacity, and the activity of enzyme systems and endocrine axes. It is now appreciated that such effects lay the foundations for a diverse array of diseases that become manifest many years later, often in response to secondary environmental stressors. Fetal development is underpinned by the placenta, the organ that forms the interface between the fetus and its mother. All nutrients and oxygen reaching the fetus must pass through this organ. The placenta also has major endocrine functions, orchestrating maternal adaptations to pregnancy and mobilizing resources for fetal use. In addition, it acts as a selective barrier, creating a protective milieu by minimizing exposure of the fetus to maternal hormones, such as glucocorticoids, xenobiotics, pathogens, and parasites. The placenta shows a remarkable capacity to adapt to adverse environmental cues and lessen their impact on the fetus. However, if placental function is impaired, or its capacity to adapt is exceeded, then fetal development may be compromised. Here, we explore the complex relationships between the placental phenotype and developmental programming of chronic disease in the offspring. Ensuring optimal placentation offers a new approach to the prevention of disorders such as cardiovascular disease, diabetes, and obesity, which are reaching epidemic proportions.
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Affiliation(s)
- Graham J Burton
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
| | - Abigail L Fowden
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
| | - Kent L Thornburg
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
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Shannon AT, Mirbod P. Three-dimensional flow patterns in the feto-placental vasculature system of the mouse placenta. Microvasc Res 2017; 111:88-95. [DOI: 10.1016/j.mvr.2017.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 01/15/2017] [Accepted: 01/15/2017] [Indexed: 11/22/2022]
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Bappoo N, Kelsey LJ, Parker L, Crough T, Moran CM, Thomson A, Holmes MC, Wyrwoll CS, Doyle BJ. Viscosity and haemodynamics in a late gestation rat feto-placental arterial network. Biomech Model Mechanobiol 2017; 16:1361-72. [PMID: 28258413 DOI: 10.1007/s10237-017-0892-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 02/21/2017] [Indexed: 12/26/2022]
Abstract
The placenta is a transient organ which develops during pregnancy to provide haemotrophic support for healthy fetal growth and development. Fundamental to its function is the healthy development of vascular trees in the feto-placental arterial network. Despite the strong association of haemodynamics with vascular remodelling mechanisms, there is a lack of computational haemodynamic data that may improve our understanding of feto-placental physiology. The aim of this work was to create a comprehensive 3D computational fluid dynamics model of a substructure of the rat feto-placental arterial network and investigate the influence of viscosity on wall shear stress (WSS). Late gestation rat feto-placental arteries were perfused with radiopaque Microfil and scanned via micro-computed tomography to capture the feto-placental arterial geometry in 3D. A detailed description of rat fetal blood viscosity parameters was developed, and three different approaches to feto-placental haemodynamics were simulated in 3D using the finite volume method: Newtonian model, non-Newtonian Carreau-Yasuda model and Fåhræus-Lindqvist effect model. Significant variability in WSS was observed between different viscosity models. The physiologically-realistic simulations using the Fåhræus-Lindqvist effect and rat fetal blood estimates of viscosity revealed detailed patterns of WSS throughout the arterial network. We found WSS gradients at bifurcation regions, which may contribute to vessel enlargement, and sprouting and pruning during angiogenesis. This simulation of feto-placental haemodynamics shows the heterogeneous WSS distribution throughout the network and demonstrates the ability to determine physiologically-relevant WSS magnitudes, patterns and gradients. This model will help advance our understanding of vascular physiology and remodelling in the feto-placental network.
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Plitman Mayo R, Olsthoorn J, Charnock-Jones D, Burton G, Oyen M. Computational modeling of the structure-function relationship in human placental terminal villi. J Biomech 2016; 49:3780-3787. [DOI: 10.1016/j.jbiomech.2016.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 10/04/2016] [Accepted: 10/04/2016] [Indexed: 12/01/2022]
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Clark AR, Kruger JA. Mathematical modeling of the female reproductive system: from oocyte to delivery. Wiley Interdiscip Rev Syst Biol Med 2016; 9. [PMID: 27612162 DOI: 10.1002/wsbm.1353] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 06/08/2016] [Accepted: 06/28/2016] [Indexed: 12/30/2022]
Abstract
From ovulation to delivery, and through the menstrual cycle, the female reproductive system undergoes many dynamic changes to provide an optimal environment for the embryo to implant, and to develop successfully. It is difficult ethically and practically to observe the system over the timescales involved in growth and development (often hours to days). Even in carefully monitored conditions clinicians and biologists can only see snapshots of the development process. Mathematical models are emerging as a key means to supplement our knowledge of the reproductive process, and to tease apart complexity in the reproductive system. These models have been used successfully to test existing hypotheses regarding the mechanisms of female infertility and pathological fetal development, and also to provide new experimentally testable hypotheses regarding the process of development. This new knowledge has allowed for improvements in assisted reproductive technologies and is moving toward translation to clinical practice via multiscale assessments of the dynamics of ovulation, development in pregnancy, and the timing and mechanics of delivery. WIREs Syst Biol Med 2017, 9:e1353. doi: 10.1002/wsbm.1353 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Alys R Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Jennifer A Kruger
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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Plitman Mayo R, Charnock-Jones DS, Burton GJ, Oyen ML. Three-dimensional modeling of human placental terminal villi. Placenta 2016; 43:54-60. [PMID: 27324100 DOI: 10.1016/j.placenta.2016.05.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/28/2016] [Accepted: 05/04/2016] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Placental transport is the main factor affecting the health and development of the fetus. Due to the placenta's geometrical and mathematical complexity, the structure-function relations of placental terminal villi have not been successfully modeled. Hence, a novel modeling approach is proposed. METHODS Computational models of four different specimens were generated from the three-dimensional reconstruction of confocal laser scanning microscopic image stacks. To evaluate the capabilities of the proposed methodology, stationary oxygen diffusion transport was calculated in the terminal villus volumes. RESULTS The reconstructions automatically provided the spatial arrangement of the fetal capillaries inside the terminal villi. The surface and volume ratios between the fetal capillaries and the villus were also calculated, and the effects of model parameters on the placental diffusive capacity were assessed by parametric analysis. DISCUSSION The potential of three-dimensional reconstructions combined with finite element analysis as a research tool for the human placenta was tested. The methodology herein could serve in the future as a simulation platform for complicated in vivo and in vitro scenarios.
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Affiliation(s)
- Romina Plitman Mayo
- Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK; Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, UK
| | - D Stephen Charnock-Jones
- Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK; Department of Obstetrics & Gynaecology, University of Cambridge, Cambridge, UK
| | - Graham J Burton
- Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Michelle L Oyen
- Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK; Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, UK.
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Serov AS, Salafia C, Grebenkov DS, Filoche M. The role of morphology in mathematical models of placental gas exchange. J Appl Physiol (1985) 2015; 120:17-28. [PMID: 26494446 DOI: 10.1152/japplphysiol.00543.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/08/2015] [Indexed: 02/07/2023] Open
Abstract
The performance of the placenta as a gas exchanger has a direct impact on the future health of the newborn. To provide accurate estimates of respiratory gas exchange rates, placenta models need to account for both the physiology of exchange and the organ morphology. While the former has been extensively studied, accounting for the latter is still a challenge. The geometrical complexity of placental structure requires use of carefully crafted approximations. We present here the state of the art of respiratory gas exchange placenta modeling and demonstrate the influence of the morphology description on model predictions. Advantages and shortcomings of various classes of models are discussed, and experimental techniques that may be used for model validation are summarized. Several directions for future development are suggested.
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Affiliation(s)
- A S Serov
- Physique de la Matière Condensée, Centre National de la Recherche Scientifique, Ecole Polytechnique, Palaiseau, France; and
| | - C Salafia
- Placental Analytics, LLC, Larchmont, New York
| | - D S Grebenkov
- Physique de la Matière Condensée, Centre National de la Recherche Scientifique, Ecole Polytechnique, Palaiseau, France; and
| | - M Filoche
- Physique de la Matière Condensée, Centre National de la Recherche Scientifique, Ecole Polytechnique, Palaiseau, France; and
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14
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Abstract
The placenta provides all the nutrients required for the fetus through pregnancy. It develops dynamically, and, to avoid rejection of the fetus, there is no mixing of fetal and maternal blood; rather, the branched placental villi 'bathe' in blood supplied from the uterine arteries. Within the villi, the feto-placental vasculature also develops a complex branching structure in order to maximize exchange between the placental and maternal circulations. To understand the development of the placenta, we must translate functional information across spatial scales including the interaction between macro- and micro-scale haemodynamics and account for the effects of a dynamically and rapidly changing structure through the time course of pregnancy. Here, we present steps towards an anatomically based and multiscale approach to modelling the feto-placental circulation. We assess the effect of the location of cord insertion on feto-placental blood flow resistance and flow heterogeneity and show that, although cord insertion does not appear to directly influence feto-placental resistance, the heterogeneity of flow in the placenta is predicted to increase from a 19.4% coefficient of variation with central cord insertion to 23.3% when the cord is inserted 2 cm from the edge of the placenta. Model geometries with spheroidal and ellipsoidal shapes, but the same volume, showed no significant differences in flow resistance or heterogeneity, implying that normal asymmetry in shape does not affect placental efficiency. However, the size and number of small capillary vessels is predicted to have a large effect on feto-placental resistance and flow heterogeneity. Using this new model as an example, we highlight the importance of taking an integrated multi-disciplinary and multiscale approach to understand development of the placenta.
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Affiliation(s)
- A R Clark
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - M Lin
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - M Tawhai
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - R Saghian
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - J L James
- Obstetrics and Gynaecology , University of Auckland , Auckland , New Zealand
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Abstract
In the human, placental structure is closely related to placental function and consequent pregnancy outcome. Studies have noted abnormal placental shape in small-for-gestational-age infants which extends to increased lifetime risk of cardiovascular disease. The origins and determinants of placental shape are incompletely understood and are difficult to study in vivo. In this paper, we model the early development of the human placenta, based on the hypothesis that this is driven by a chemoattractant effect emanating from proximal spiral arteries in the decidua. We derive and explore a two-dimensional stochastic model, and investigate the effects of loss of spiral arteries in regions near to the cord insertion on the shape of the placenta. This model demonstrates that disruption of spiral arteries can exert profound effects on placental shape, particularly if this is close to the cord insertion. Thus, placental shape reflects the underlying maternal vascular bed. Abnormal placental shape may reflect an abnormal uterine environment, predisposing to pregnancy complications. Through statistical analysis of model placentas, we are able to characterize the probability that a given placenta grew in a disrupted environment, and even able to distinguish between different disruptions.
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Affiliation(s)
- Simon L Cotter
- School of Mathematics, University of Manchester, Oxford Road, Manchester, UK
| | - Václav Klika
- Department of Mathematics, FNSPE, Czech Technical University in Prague, Trojanova 13, Prague 2 12000, Czech Republic Mathematical Institute, University of Oxford, Woodstock Road, Oxford, UK
| | - Laura Kimpton
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford, UK
| | - Sally Collins
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Oxford, UK Fetal Medicine Unit, John Radcliffe Hospital, Oxford, UK
| | - Alexander E P Heazell
- Institute of Human Development, Maternal and Fetal Health Research Centre, University of Manchester, Manchester, UK Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
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Abstract
Numerous studies have addressed the significance of marginal and membranous umbilical cord (UC) insertion. Recent reports suggest that an eccentrically inserted UC may also be important. This case-control study assessed the potential relevance of peripheral insertion of UC (PIUC), defined as <3 cm from the nearest margin. Singleton placentas (n = 1418) submitted to the pathology department over an 18-month period were analyzed. Each case of PIUC (n = 119) was matched with a control placenta of the same gestational age. Placentas with marginal or membranous UC and multiple gestations were excluded. The overall prevalence of PIUC was 8.4%, but PIUC frequency was significantly increased in premature births at <28 weeks (21.4%, P < 0.001). There was no association with other adverse pregnancy outcomes. PIUC was associated with decreased placental weight Z-score (-0.69 ± 0.92 versus -0.22 ± 1.3, P = 0.0056), but not fetal weight Z-score, suggesting increased utilization of placental reserve. PIUC was also associated with relatively elongated placentas (length minus width: 2.6 ± 3.2 versus 1.0 ± 3.1, P = 0.006). PIUC tended to be more frequent in young primiparous mothers and was significantly less common in women with a history of prior curettage (66% vs 50%, P = 0.013). These data, together with equivalent rates of prior cesarean section, multiparity, and advanced maternal age, support a primary developmental disorder as opposed to secondary placental migration due to underlying uterine abnormalities ("trophotropism"). Except for a borderline significant association with findings suggestive of maternal malperfusion (P = 0.078), PIUC was not associated with other placental lesions.
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Affiliation(s)
- Guangju Luo
- 1 Department of Pathology, University Hospitals Case Medical Center and Case Western Reserve University, Cleveland, OH, USA
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Abstract
Normal fetal development is dependent on adequate placental blood perfusion. The functional role of the placenta takes place mainly in the capillary system; however, ultrasound imaging of fetal blood flow is commonly performed on the umbilical artery, or on its first branches over the chorionic plate. The objective of this study was to evaluate the structural organization of the feto-placental vasculature of the chorionic plate. Casting of the placental vasculature was performed on 15 full-term placentas using a dental polymer mixed with colored ink. Observations of the cast models revealed that the branching architecture of the chorionic vessel is a combination of dichotomous and monopodial patterns, where the first two to three generations are always of a dichotomous nature. Analysis of the daughter-to-mother diameter ratios in the chorionic vessels provided a maximum in the range of 0.6-0.8 for the dichotomous branches, whereas in monopodial branches it was in the range of 0.1-0.3. Similar to previous studies, this study reveals that the vasculature architecture is mostly monopodial for the marginal cord insertion and mostly dichotomous for the central insertion. The more marginal the umbilical cord insertion is on the chorionic plate, the more monopodial branching patterns are created to compensate the dichotomous pattern deficiency to perfuse peripheral placental territories.
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Affiliation(s)
- Z Gordon
- Department of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University, Israel.
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