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Kühle H, Cho SKS, Barber N, Goolaub DS, Darby JRT, Morrison JL, Haller C, Sun L, Seed M. Advanced imaging of fetal cardiac function. Front Cardiovasc Med 2023; 10:1206138. [PMID: 37288263 PMCID: PMC10242056 DOI: 10.3389/fcvm.2023.1206138] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/09/2023] [Indexed: 06/09/2023] Open
Abstract
Over recent decades, a variety of advanced imaging techniques for assessing cardiovascular physiology and cardiac function in adults and children have been applied in the fetus. In many cases, technical development has been required to allow feasibility in the fetus, while an appreciation of the unique physiology of the fetal circulation is required for proper interpretation of the findings. This review will focus on recent advances in fetal echocardiography and cardiovascular magnetic resonance (CMR), providing examples of their application in research and clinical settings. We will also consider future directions for these technologies, including their ongoing technical development and potential clinical value.
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Affiliation(s)
- Henriette Kühle
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Department of Cardiac and Thoracic Surgery, University Hospital Magdeburg, Otto von Guericke University Magdeburg, Magdeburg, Germany
- Division of Cardiac Surgery, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Steven K. S. Cho
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia
| | - Nathaniel Barber
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Datta Singh Goolaub
- Translational Medicine Program, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Jack R. T. Darby
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia
| | - Janna L. Morrison
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia
- Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Christoph Haller
- Division of Cardiac Surgery, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Liqun Sun
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Translational Medicine Program, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Mike Seed
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Translational Medicine Program, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
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2
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Lear CA, Beacom MJ, Dhillon SK, Lear BA, Mills OJ, Gunning MI, Westgate JA, Bennet L, Gunn AJ. Dissecting the contributions of the peripheral chemoreflex and myocardial hypoxia to fetal heart rate decelerations in near-term fetal sheep. J Physiol 2023; 601:2017-2041. [PMID: 37017488 DOI: 10.1113/jp284286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/30/2023] [Indexed: 04/06/2023] Open
Abstract
Brief repeated fetal hypoxaemia during labour can trigger intrapartum decelerations of the fetal heart rate (FHR) via the peripheral chemoreflex or the direct effects of myocardial hypoxia, but the relative contribution of these two mechanisms and how this balance changes with evolving fetal compromise remain unknown. In the present study, chronically instrumented near-term fetal sheep received surgical vagotomy (n = 8) or sham vagotomy (control, n = 11) to disable the peripheral chemoreflex and unmask myocardial hypoxia. One-minute complete umbilical cord occlusions (UCOs) were performed every 2.5 min for 4 h or until arterial pressure fell below 20 mmHg. Hypotension and severe acidaemia developed progressively after 65.7 ± 7.2 UCOs in control fetuses and 49.5 ± 7.8 UCOs after vagotomy. Vagotomy was associated with faster development of metabolic acidaemia and faster impairment of arterial pressure during UCOs without impairing centralization of blood flow or neurophysiological adaptation to UCOs. During the first half of the UCO series, before severe hypotension developed, vagotomy was associated with a marked increase in FHR during UCOs. After the onset of evolving severe hypotension, FHR fell faster in control fetuses during the first 20 s of UCOs, but FHR during the final 40 s of UCOs became progressively more similar between groups, with no difference in the nadir of decelerations. In conclusion, FHR decelerations were initiated and sustained by the peripheral chemoreflex at a time when fetuses were able to maintain arterial pressure. After the onset of evolving hypotension and acidaemia, the peripheral chemoreflex continued to initiate decelerations, but myocardial hypoxia became progressively more important in sustaining and deepening decelerations. KEY POINTS: Brief repeated hypoxaemia during labour can trigger fetal heart rate decelerations by either the peripheral chemoreflex or myocardial hypoxia, but how this balance changes with fetal compromise is unknown. Reflex control of fetal heart rate was disabled by vagotomy to unmask the effects of myocardial hypoxia in chronically instrumented fetal sheep. Fetuses were then subjected to repeated brief hypoxaemia consistent with the rates of uterine contractions during labour. We show that the peripheral chemoreflex controls brief decelerations in their entirety at a time when fetuses were able to maintain normal or increased arterial pressure. The peripheral chemoreflex still initiated decelerations even after the onset of evolving hypotension and acidaemia, but myocardial hypoxia made an increasing contribution to sustain and deepen decelerations.
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Affiliation(s)
- Christopher A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Michael J Beacom
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Simerdeep K Dhillon
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Benjamin A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Olivia J Mills
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Mark I Gunning
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Jenny A Westgate
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
- Department of Paediatrics, Starship Children's Hospital, Auckland, New Zealand
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3
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Lear CA, Georgieva A, Beacom MJ, Wassink G, Dhillon SK, Lear BA, Mills OJ, Westgate JA, Bennet L, Gunn AJ. Fetal heart rate responses in chronic hypoxaemia with superimposed repeated hypoxaemia consistent with early labour: a controlled study in fetal sheep. BJOG 2023. [PMID: 36808862 DOI: 10.1111/1471-0528.17425] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 01/30/2023] [Accepted: 02/09/2023] [Indexed: 02/20/2023]
Abstract
OBJECTIVE Deceleration area (DA) and capacity (DC) of the fetal heart rate can help predict risk of intrapartum fetal compromise. However, their predictive value in higher risk pregnancies is unclear. We investigated whether they can predict the onset of hypotension during brief hypoxaemia repeated at a rate consistent with early labour in fetal sheep with pre-existing hypoxaemia. DESIGN Prospective, controlled study. SETTING Laboratory. SAMPLE Chronically instrumented, unanaesthetised near-term fetal sheep. METHODS One-minute complete umbilical cord occlusions (UCOs) were performed every 5 minutes in fetal sheep with baseline pa O2 <17 mmHg (hypoxaemic, n = 8) and >17 mmHg (normoxic, n = 11) for 4 hours or until arterial pressure fell <20 mmHg. MAIN OUTCOME MEASURES DA, DC and arterial pressure. RESULTS Normoxic fetuses showed effective cardiovascular adaptation without hypotension and mild acidaemia (lowest arterial pressure 40.7 ± 2.8 mmHg, pH 7.35 ± 0.03). Hypoxaemic fetuses developed hypotension (lowest arterial pressure 20.8 ± 1.9 mmHg, P < 0.001) and acidaemia (final pH 7.07 ± 0.05). In hypoxaemic fetuses, decelerations showed faster falls in FHR over the first 40 seconds of UCOs but the final deceleration depth was not different to normoxic fetuses. DC was modestly higher in hypoxaemic fetuses during the penultimate (P = 0.04) and final (P = 0.012) 20 minutes of UCOs. DA was not different between groups. CONCLUSION Chronically hypoxaemic fetuses had early onset of cardiovascular compromise during labour-like brief repeated UCOs. DA was unable to identify developing hypotension in this setting, while DC only showed modest differences between groups. These findings highlight that DA and DC thresholds need to be adjusted for antenatal risk factors, potentially limiting their clinical utility.
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Affiliation(s)
- C A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - A Georgieva
- Nuffield Department of Women's and Reproductive Health, The John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - M J Beacom
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - G Wassink
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - S K Dhillon
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - B A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - O J Mills
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - J A Westgate
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - L Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - A J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.,Starship Children's Hospital, Auckland, New Zealand
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Dimasi CG, Lazniewska J, Plush SE, Saini BS, Holman SL, Cho SKS, Wiese MD, Sorvina A, Macgowan CK, Seed M, Brooks DA, Morrison JL, Darby JRT. Redox ratio in the left ventricle of the growth restricted fetus is positively correlated with cardiac output. JOURNAL OF BIOPHOTONICS 2021; 14:e202100157. [PMID: 34499415 DOI: 10.1002/jbio.202100157] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Intrauterine growth restriction (IUGR) is a result of limited substrate supply to the developing fetus in utero, and can be caused by either placental, genetic or environmental factors. Babies born IUGR can have poor long-term health outcomes, including being at higher risk of developing cardiovascular disease. Limited substrate supply in the IUGR fetus not only changes the structure of the heart but may also affect metabolism and function of the developing heart. We have utilised two imaging modalities, two-photon microscopy and phase-contrast MRI (PC-MRI), to assess alterations in cardiac metabolism and function using a sheep model of IUGR. Two-photon imaging revealed that the left ventricle of IUGR fetuses (at 140-141 d GA) had a reduced optical redox ratio, suggesting a reliance on glycolysis for ATP production. Concurrently, the use of PC-MRI to measure foetal left ventricular cardiac output (LVCO) revealed a positive correlation between LVCO and redox ratio in IUGR, but not control fetuses. These data suggest that altered heart metabolism in IUGR fetuses is indicative of reduced cardiac output, which may contribute to poor cardiac outcomes in adulthood.
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Affiliation(s)
- Catherine G Dimasi
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Joanna Lazniewska
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Sally E Plush
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Steven K S Cho
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Wiese
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mike Seed
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Bodine SC, Brooks HL, Bunnett NW, Coller HA, Frey MR, Joe B, Kleyman TR, Lindsey ML, Marette A, Morty RE, Ramírez JM, Thomsen MB, Yosten GLC. An American Physiological Society cross-journal Call for Papers on "Inter-Organ Communication in Homeostasis and Disease". Am J Physiol Lung Cell Mol Physiol 2021; 321:L42-L49. [PMID: 34010064 PMCID: PMC8321848 DOI: 10.1152/ajplung.00209.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 12/17/2022] Open
Affiliation(s)
- Sue C Bodine
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Heddwen L Brooks
- Department of Physiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Nigel W Bunnett
- Department of Molecular Pathobiology, New York University, New York, New York
| | - Hilary A Coller
- Molecular Biology Interdepartmental Program, University of California, Los Angeles, California
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California
- Department of Biological Chemistry, University of California, Los Angeles, California
| | - Mark R Frey
- The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, California
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Bina Joe
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio
- Center for Hypertension and Personalized Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio
| | - Thomas R Kleyman
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Merry L Lindsey
- Department of Cellular and Integrative Physiology, Center for Heart and Vascular Research, University of Nebraska Medical Center, Omaha, Nebraska
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - André Marette
- Department of Medicine, Faculty of Medicine, Cardiology Axis of the Québec Heart and Lung Institute, Hôpital Laval, Laval University, Quebec City, Québec, Canada
- Institute of Nutrition and Functional Foods, Laval University, Quebec City, Québec, Canada
| | - Rory E Morty
- Department of Translational Pulmonology and the Translational Lung Research Center Heidelberg, University Hospital Heidelberg, member of the German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
- Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, Justus Liebig University Giessen, member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Jan-Marino Ramírez
- Department of Neurological Surgery, University of Washington Medical Center, Seattle, Washington
- Center on Human Development and Disability, University of Washington, Seattle, Washington
- Center for Integrative Brain Research at the Seattle Children's Research Institute, University of Washington, Seattle, Washington
| | - Morten B Thomsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gina L C Yosten
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri
- Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis University School of Medicine, St. Louis, Missouri
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Saini BS, Darby JRT, Marini D, Portnoy S, Lock MC, Yin Soo J, Holman SL, Perumal SR, Wald RM, Windrim R, Macgowan CK, Kingdom JC, Morrison JL, Seed M. An MRI approach to assess placental function in healthy humans and sheep. J Physiol 2021; 599:2573-2602. [PMID: 33675040 DOI: 10.1113/jp281002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/15/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Human placental function is evaluated using non-invasive Doppler ultrasound of umbilical and uterine artery pulsatility indices as measures of resistance in placental vascular beds, while measurement of placental oxygen consumption ( V O 2 ) is only possible during Caesarean delivery. This study shows the feasibility of using magnetic resonance imaging (MRI) in utero to measure blood flow and oxygen content in uterine and umbilical vessels to calculate oxygen delivery to and V O 2 by the gravid uterus, uteroplacenta and fetus. Normal late gestational human uteroplacental V O 2 by MRI was ∼4 ml min-1 kg-1 fetal weight, which was similar to our MRI measurements in sheep and to those previously measured using invasive techniques. Our MRI approach can quantify uteroplacental V O 2 , which involves the quantification of maternal- and fetal-placental blood flows, fetal oxygen delivery and V O 2 , and the oxygen gradient between uterine- and umbilical-venous blood, providing a comprehensive assessment of placental function with clinical potential. ABSTRACT It has not been feasible to perform routine clinical measurement of human placental oxygen consumption ( V O 2 ) and in vitro studies do not reflect true metabolism in utero. Here we propose an MRI method to non-invasively quantify in utero placental and fetal oxygen delivery ( D O 2 ) and V O 2 in healthy humans and sheep. Women (n = 20) and Merino sheep (n = 10; 23 sets of measurements) with singleton pregnancies underwent an MRI in late gestation (36 ± 2 weeks and 128 ± 9 days, respectively; mean ± SD). Blood flow (phase-contrast) and oxygen content (T1 and T2 relaxometry) were measured in the major uterine- and umbilical-placental vessels, allowing calculation of uteroplacental and fetal D O 2 and V O 2 . Maternal D O 2 (ml min-1 kg-1 fetus) to the gravid uterus was similar in humans and sheep (human = 54 ± 15, sheep = 53 ± 21, P = 0.854), while fetal D O 2 (human = 25 ± 4, sheep = 22 ± 5, P = 0.049) was slightly lower in sheep. Uteroplacental and fetal V O 2 (ml min-1 kg-1 fetus; uteroplacental: human = 4.1 ± 1.5, sheep = 3.5 ± 1.9, P = 0.281; fetus: human = 6.8 ± 1.3, sheep = 7.2 ± 1.7, P = 0.426) were similar between species. Late gestational uteroplacental:fetal V O 2 ratio did not change with age (human, P = 0.256; sheep, P = 0.121). Human umbilical blood flow (ml min-1 kg-1 fetus) decreased with advancing age (P = 0.008), while fetal V O 2 was preserved through an increase in oxygen extraction (P = 0.046). By contrast, sheep fetal V O 2 was preserved through stable umbilical flow (ml min-1 kg-1 ; P = 0.443) and oxygen extraction (P = 0.582). MRI derived measurements of uteroplacental and fetal V O 2 between humans and sheep were similar and in keeping with prior data obtained using invasive techniques. Taken together, these data confirm the reliability of our approach, which offers a novel clinical 'placental function test'.
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Affiliation(s)
- Brahmdeep S Saini
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Division of Cardiology, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Davide Marini
- Division of Cardiology, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada
| | - Sharon Portnoy
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sunthara R Perumal
- Preclinical, Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, South Australia, 5086, Australia
| | - Rachel M Wald
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, ON, M5G 2N2, Canada
| | - Rory Windrim
- Maternal-Fetal Medicine Division, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1E2, Canada
| | - Christopher K Macgowan
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - John C Kingdom
- Maternal-Fetal Medicine Division, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1E2, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mike Seed
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Division of Cardiology, Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.,Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Obstetrics and Gynaecology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1E2, Canada
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7
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Aujla T, Darby JRT, Saini BS, Lock MC, Holman SL, Bradshaw EL, Perumal SR, McInnes SJP, Voelcker NH, Wiese MD, Macgowan CK, Seed M, Morrison JL. Impact of resveratrol-mediated increase in uterine artery blood flow on fetal haemodynamics, blood pressure and oxygenation in sheep. Exp Physiol 2021; 106:1166-1180. [PMID: 33600040 DOI: 10.1113/ep089237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/15/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Uterine artery blood flow helps to maintain fetal oxygen and nutrient delivery. We investigated the effects of increased uterine artery blood flow mediated by resveratrol on fetal growth, haemodynamics, blood pressure regulation and oxygenation in pregnant sheep. What is the main finding and its importance? Fetuses from resveratrol-treated ewes were significantly larger and exhibited a haemodynamic profile that might promote peripheral growth. Absolute uterine artery blood flow was positively correlated with umbilical vein oxygen saturation, absolute fetal oxygen delivery and fetal growth. Increasing uterine artery blood flow with compounds such as resveratrol might have clinical significance for pregnancy conditions in which fetal growth and oxygenation are compromised. ABSTRACT High placental vascular resistance hinders uterine artery (UtA) blood flow and fetal substrate delivery. In the same group of animals as the present study, we have previously shown that resveratrol (RSV) increases UtA blood flow, fetal weight and oxygenation in an ovine model of human pregnancy. However, the mechanisms behind changes in growth and the effects of increases in UtA blood flow on fetal circulatory physiology have yet to be investigated. Twin-bearing ewes received s.c. vehicle (VEH, n = 5) or RSV (n = 6) delivery systems at 113 days of gestation (term = 150 days). Magnetic resonance imaging was performed at 123-124 days to quantify fetal volume, blood flow and oxygen saturation of major fetal vessels. At 128 days, i.v. infusions of sodium nitroprusside and phenylephrine were administered to study the vascular tone of the fetal descending aorta. Maternal RSV increased fetal body volume (P = 0.0075) and weight (P = 0.0358), with no change in brain volume or brain weight. There was a positive relationship between absolute UtA blood flow and umbilical vein oxygen saturation, absolute fetal oxygen delivery and combined fetal twin volume (all P ≤ 0.05). There were no differences between groups in fetal haemodynamics or blood pressure regulation except for higher blood flow to the lower body in RSV fetuses (P = 0.0170). The observed increase in fetal weight might be helpful in pregnancy conditions in which fetal growth and oxygen delivery are compromised. Further preclinical investigations on the mechanism(s) accounting for these changes and the potential to improve growth in complicated pregnancies are warranted.
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Affiliation(s)
- Tanroop Aujla
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, South Australia, Australia
| | - Steven J P McInnes
- UniSA STEM, University of South Australia, Adelaide, South Australia, Australia
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Clayton, Victoria, Australia.,Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
| | - Michael D Wiese
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mike Seed
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Flouri D, Darby JRT, Holman SL, Perumal SR, David AL, Morrison JL, Melbourne A. Magnetic resonance imaging of placentome development in the pregnant Ewe. Placenta 2021; 105:61-69. [PMID: 33549925 PMCID: PMC7611430 DOI: 10.1016/j.placenta.2021.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/08/2021] [Accepted: 01/15/2021] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Novel imaging measurements of placental development are difficult to validate due to the invasive nature of gold-standard procedures. Animal studies have been important in validation of magnetic resonance imaging (MRI) measurements in invasive preclinical studies, as they allow for controlled experiments and analysis of multiple time-points during pregnancy. This study characterises the longitudinal diffusion and perfusion properties of sheep placentomes using MRI, measurements that are required for future validation studies. METHODS Pregnant ewes were anaesthetised for a MRI session on a 3T scanner. Placental MRI was used to classify placentomes morphologically into three types based on their shape and size at two gestational ages. To validate classification accuracy, placentome type derived from MRI data were compared with placentome categorisation results after delivery. Diffusion-Weighted MRI and T2-relaxometry were used to measure a broad range of biophysical properties of the placentomes. RESULTS MRI morphological classification results showed consistent gestational age changes in placentome shape, as supported by post-delivery gold standard data. The mean apparent diffusion coefficient was significantly higher at 110 days gestation than at late gestation (~140 days; term, 150 days). Mean T2 was higher at mid gestation (152.2 ± 58.1 ms) compared to late gestation (127.8 ms ± 52.0). Significantly higher perfusion fraction was measured in late gestation placentomes that also had a significantly higher fractional anisotropy when compared to the earlier gestational age. DISCUSSION We report baseline measurements of techniques common in placental MRI for the sheep placenta. These measurements are essential to support future validation measurements of placental MRI techniques.
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Affiliation(s)
- Dimitra Flouri
- School of Biomedical Engineering and Imaging Sciences, Kings College London, London, United Kingdom; Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom.
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
| | - Sunthara R Perumal
- South Australian Health & Medical Research Institute, Preclinical, Imaging & Research Laboratories, Adelaide, Australia
| | - Anna L David
- Elizabeth Garrett Anderson Institute for Women's Health, University College London, London, London, United Kingdom; NIHR Biomedical Research Centre, University College London Hospitals, London, United Kingdom
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging Sciences, Kings College London, London, United Kingdom; Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom; Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
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Darby JRT, Schrauben EM, Saini BS, Holman SL, Perumal SR, Seed M, Macgowan CK, Morrison JL. Umbilical vein infusion of prostaglandin I 2 increases ductus venosus shunting of oxygen-rich blood but does not increase cerebral oxygen delivery in the fetal sheep. J Physiol 2020; 598:4957-4967. [PMID: 32776527 DOI: 10.1113/jp280019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/27/2020] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS The ductus venosus (DV) is a dynamic fetal shunt that allows substrate-rich blood from the umbilical vein to bypass the hepatic circulation. In vitro studies suggest a direct role of prostaglandin I2 (PGI2 ) in the regulation of DV tone; however, the extent of this regulation has not been determined in utero. 4D flow and T2 oximetry magnetic resonance imaging can be combined to determine blood flow and oxygen delivery within the fetal circulation. PGI2 increases DV shunting of substrate-rich blood but this does not increase cerebral oxygen delivery. ABSTRACT During fetal development, the maintenance of adequate oxygen and nutrient supply to vital organs is regulated through specialized fetal shunts. One of these shunts, the ductus venosus (DV), allows oxygen-rich blood to preferentially stream from the placenta toward the heart and brain. Herein, we combine magnetic resonance imaging (MRI) techniques that measure blood flow (4D flow) and oxygen saturation (T2 oximetry) in the fetal circuit to determine whether umbilical vein infusion of prostaglandin I2 (PGI2 , regulator of DV tone ex utero) directly dilates the DV and thus increases the preferential streaming of oxygen-rich blood toward the brain. At 114-115 days gestational age (dGA; term = 150 days), fetal sheep (n = 6) underwent surgery to implant vascular catheters in the fetal femoral artery, femoral vein, amniotic cavity and umbilical vein. Fetal MRI scans were performed at 119-124 dGA. 4D flow and T2 oximetry were performed to measure blood flow and oxygen saturation across the fetal circulation in both a basal state and whilst the fetus was receiving a continuous infusion of PGI2 . The proportion of oxygenated blood that passed through the DV from the umbilical vein was increased by PGI2 . Cerebral oxygen delivery was unchanged in the PGI2 state. This may be a result of decreased flow from the right to left side of the heart as blood flow through the foramen ovale was decreased by PGI2 . We have shown that although PGI2 acts on the DV to increase the proportion of oxygen-rich blood that bypasses the liver, this does not increase cerebral oxygen delivery in the fetal sheep.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Eric M Schrauben
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brahmdeep S Saini
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Sunthara Rajan Perumal
- Preclinical, Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
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