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Malvasi A, Baldini GM, Cicinelli E, Di Naro E, Baldini D, Favilli A, Quellari PT, Sabbatini P, Fioretti B, Malgieri LE, Damiani GR, Dellino M, Trojano G, Tinelli A. Localization of Catecholaminergic Neurofibers in Pregnant Cervix as a Possible Myometrial Pacemaker. Int J Mol Sci 2024; 25:5630. [PMID: 38891818 PMCID: PMC11171499 DOI: 10.3390/ijms25115630] [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: 03/13/2024] [Revised: 04/27/2024] [Accepted: 05/14/2024] [Indexed: 06/21/2024] Open
Abstract
In eutocic labor, the autonomic nervous system is dominated by the parasympathetic system, which ensures optimal blood flow to the uterus and placenta. This study is focused on the detection of the quantitative presence of catecholamine (C) neurofibers in the internal uterine orifice (IUO) and in the lower uterine segment (LUS) of the pregnant uterus, which could play a role in labor and delivery. A total of 102 women were enrolled before their submission to a scheduled cesarean section (CS); patients showed a singleton fetus in a cephalic presentation outside labor. During CS, surgeons sampled two serial consecutive full-thickness sections 5 mm in depth (including the myometrial layer) on the LUS and two randomly selected samples of 5 mm depth from the IUO of the cervix. All histological samples were studied to quantify the distribution of A nerve fibers. The authors demonstrated a significant and notably higher concentration of A fibers in the IUO (46 ± 4.8) than in the LUS (21 ± 2.6), showing that the pregnant cervix has a greater concentration of A neurofibers than the at-term LUS. Pregnant women's mechanosensitive pacemakers can operate normally when the body is in a physiological state, which permits normal uterine contractions and eutocic delivery. The increased frequency of C neurofibers in the cervix may influence the smooth muscle cell bundles' activation, which could cause an aberrant mechano-sensitive pacemaker activation-deactivation cycle. Stressful circumstances (anxiety, tension, fetal head position) cause the sympathetic nervous system to become more active, working through these nerve fibers in the gravid cervix. They might interfere with the mechano-sensitive pacemakers, slowing down the uterine contractions and cervix ripening, which could result in dystocic labor.
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Affiliation(s)
- Antonio Malvasi
- 1st Unit of Gynecology and Obstetrics, Department of Interdisciplinary Medicine (DIM), University of Bari (BA), 70124 Bari, Italy; (A.M.); (G.M.B.); (E.C.); (E.D.N.); (G.R.D.); (M.D.)
| | - Giorgio Maria Baldini
- 1st Unit of Gynecology and Obstetrics, Department of Interdisciplinary Medicine (DIM), University of Bari (BA), 70124 Bari, Italy; (A.M.); (G.M.B.); (E.C.); (E.D.N.); (G.R.D.); (M.D.)
| | - Ettore Cicinelli
- 1st Unit of Gynecology and Obstetrics, Department of Interdisciplinary Medicine (DIM), University of Bari (BA), 70124 Bari, Italy; (A.M.); (G.M.B.); (E.C.); (E.D.N.); (G.R.D.); (M.D.)
| | - Edoardo Di Naro
- 1st Unit of Gynecology and Obstetrics, Department of Interdisciplinary Medicine (DIM), University of Bari (BA), 70124 Bari, Italy; (A.M.); (G.M.B.); (E.C.); (E.D.N.); (G.R.D.); (M.D.)
| | | | - Alessandro Favilli
- Department of Medicine and Surgery, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy; (A.F.); (P.T.Q.)
| | - Paola Tiziana Quellari
- Department of Medicine and Surgery, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy; (A.F.); (P.T.Q.)
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via dell’Elce di Sotto 8, 06132 Perugia, Italy; (P.S.); (B.F.)
- ASST Grande Ospedale Metropolitano Niguarda, 20162 Milano, Italy
| | - Paola Sabbatini
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via dell’Elce di Sotto 8, 06132 Perugia, Italy; (P.S.); (B.F.)
| | - Bernard Fioretti
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via dell’Elce di Sotto 8, 06132 Perugia, Italy; (P.S.); (B.F.)
| | | | - Gianluca Raffaello Damiani
- 1st Unit of Gynecology and Obstetrics, Department of Interdisciplinary Medicine (DIM), University of Bari (BA), 70124 Bari, Italy; (A.M.); (G.M.B.); (E.C.); (E.D.N.); (G.R.D.); (M.D.)
| | - Miriam Dellino
- 1st Unit of Gynecology and Obstetrics, Department of Interdisciplinary Medicine (DIM), University of Bari (BA), 70124 Bari, Italy; (A.M.); (G.M.B.); (E.C.); (E.D.N.); (G.R.D.); (M.D.)
| | - Giuseppe Trojano
- Department of Maternal and Child, Madonna delle Grazie Hospital ASM, 75100 Matera, Italy;
| | - Andrea Tinelli
- Department of Gynaecology and Obstetrics, CERICSAL (CEntro di RIcerca Clinico SALentino), “Veris delli Ponti Hospital”, 73020 Lecce, Italy
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2
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Fidalgo DS, Jorge RMN, Parente MPL, Louwagie EM, Malanowska E, Myers KM, Oliveira DA. Pregnancy state before the onset of labor: a holistic mechanical perspective. Biomech Model Mechanobiol 2024:10.1007/s10237-024-01853-3. [PMID: 38758337 DOI: 10.1007/s10237-024-01853-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 04/17/2024] [Indexed: 05/18/2024]
Abstract
Successful pregnancy highly depends on the complex interaction between the uterine body, cervix, and fetal membrane. This interaction is synchronized, usually following a specific sequence in normal vaginal deliveries: (1) cervical ripening, (2) uterine contractions, and (3) rupture of fetal membrane. The complex interaction between the cervix, fetal membrane, and uterine contractions before the onset of labor is investigated using a complete third-trimester gravid model of the uterus, cervix, fetal membrane, and abdomen. Through a series of numerical simulations, we investigate the mechanical impact of (i) initial cervical shape, (ii) cervical stiffness, (iii) cervical contractions, and (iv) intrauterine pressure. The findings of this work reveal several key observations: (i) maximum principal stress values in the cervix decrease in more dilated, shorter, and softer cervices; (ii) reduced cervical stiffness produces increased cervical dilation, larger cervical opening, and decreased cervical length; (iii) the initial cervical shape impacts final cervical dimensions; (iv) cervical contractions increase the maximum principal stress values and change the stress distributions; (v) cervical contractions potentiate cervical shortening and dilation; (vi) larger intrauterine pressure (IUP) causes considerably larger stress values and cervical opening, larger dilation, and smaller cervical length; and (vii) the biaxial strength of the fetal membrane is only surpassed in the cases of the (1) shortest and most dilated initial cervical geometry and (2) larger IUP.
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Affiliation(s)
- Daniel S Fidalgo
- Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), R. Dr. Roberto Frias 400, 4200-465, Porto, Portugal.
- Mechanical Department (DEMec), Faculty of Engineering of University of Porto (FEUP), R. Dr. Roberto Frias, 4200-465, Porto, Portugal.
| | - Renato M Natal Jorge
- Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), R. Dr. Roberto Frias 400, 4200-465, Porto, Portugal
- Mechanical Department (DEMec), Faculty of Engineering of University of Porto (FEUP), R. Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Marco P L Parente
- Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), R. Dr. Roberto Frias 400, 4200-465, Porto, Portugal
- Mechanical Department (DEMec), Faculty of Engineering of University of Porto (FEUP), R. Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Erin M Louwagie
- Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA
| | - Ewelina Malanowska
- Department of Gynaecology, Endocrinology and Gynaecologic Oncology, Pomeranian Medical University, Szczecin, Poland
| | - Kristin M Myers
- Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA
| | - Dulce A Oliveira
- Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), R. Dr. Roberto Frias 400, 4200-465, Porto, Portugal
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3
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Combs DJ, Moult EM, England SK, Cohen AE. Mapping uterine calcium dynamics during the ovulatory cycle in live mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.02.578395. [PMID: 38370720 PMCID: PMC10871303 DOI: 10.1101/2024.02.02.578395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Uterine contraction patterns vary during the ovulatory cycle and throughout pregnancy but prior measurements have produced limited and conflicting information on these patterns. We combined a virally delivered genetically encoded calcium reporter (GCaMP8m) and ultra-widefield imaging in live nonpregnant mice to characterize uterine calcium dynamics at organ scale throughout the estrous cycle. Prior to ovulation (proestrus and estrus) uterine excitations primarily initiated in a region near the oviduct, but after ovulation (metestrus and diestrus), excitations initiated at loci homogeneously distributed throughout the organ. The frequency of excitation events was lowest in proestrus and estrus, higher in metestrus and highest in diestrus. These results establish a platform for mapping uterine activity, and show that the question of whether there is an anatomically localized trigger for uterine excitations depends on the estrous cycle phase.
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Affiliation(s)
- David J. Combs
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School
- Department of Chemistry and Chemical Biology, Harvard University
| | - Eric M. Moult
- Department of Chemistry and Chemical Biology, Harvard University
| | - Sarah K. England
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University School of Medicine
| | - Adam E. Cohen
- Department of Chemistry and Chemical Biology, Harvard University
- Department of Physics, Harvard University
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4
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Malvasi A, Ballini A, Tinelli A, Fioretti B, Vimercati A, Gliozheni E, Baldini GM, Cascardi E, Dellino M, Bonetti M, Cicinelli E, Vitagliano A, Damiani GR. Oxytocin augmentation and neurotransmitters in prolonged delivery: An experimental appraisal. Eur J Obstet Gynecol Reprod Biol X 2024; 21:100273. [PMID: 38274243 PMCID: PMC10809121 DOI: 10.1016/j.eurox.2023.100273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 12/22/2023] [Indexed: 01/27/2024] Open
Abstract
The uterus is a highly innervated organ, and during labor, this innervation is at its highest level. Oxytocinergic fibers play an important role in labor and delivery and, in particular, the Lower Uterine Segment, cervix, and fundus are all controlled by motor neurofibers. Oxytocin is a neurohormone that acts on receptors located on the membrane of the smooth cells of the myometrium. During the stages of labor and delivery, its binding causes myofibers to contract, which enables the fundus of the uterus to act as a mediator. The aim of this study was to investigate the presence of oxytocinergic fibers in prolonged and non-prolonged dystocic delivery in a cohort of 90 patients, evaluated during the first and second stages of labor. Myometrial tissue samples were collected and evaluated by electron microscopy, in order to quantify differences in neurofibers concentrations between the investigated and control cohorts of patients. The authors of this experiment showed that the concentration of oxytocinergic fibers differs between non-prolonged and prolonged dystocic delivery. In particular, in prolonged dystocic delivery, compared to non-prolonged dystocic delivery, there is a lower amount of oxytocin fiber. The increase in oxytocin appeared to be ineffective in patients who experienced prolonged dystocic delivery, since the dystocic labor ended as a result of the altered presence of oxytocinergic fibers detected in this group of patients.
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Affiliation(s)
- Antonio Malvasi
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
| | - Andrea Ballini
- Department of clinical and experimental medicine, University of Foggia, Foggia, 71122, Italy
| | - Andrea Tinelli
- Department of Obstetrics and Gynecology and CERICSAL (CEntro di RIcerca Clinico SALentino), Veris Delli Ponti Hospital, 73020 Scorrano, Italy
| | - Bernard Fioretti
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via dell'Elce di Sotto 8, 06132 Perugia, Italy
| | - Antonella Vimercati
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
| | - Elko Gliozheni
- Section of Obstetrics and Gynecology, Department of Medicine and Surgery, University of Perugia, 06156 Perugia, Italy
- University of Medicine of Tirana, Department of Obstetrics and Gynecology, Tirana, Albania
| | - Giorgio Maria Baldini
- Momo Fertilife, IVF Clinic, Bisceglie, 76011, Italy
- University of Bari Aldo Moro, 70121, Bari, Italy
| | - Eliano Cascardi
- Department of Precision and Regenerative Medicine and Ionian Area, University of Bari “Aldo Moro”, Policlinico of Bari, Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Miriam Dellino
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
| | - Monica Bonetti
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
| | - Ettore Cicinelli
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
| | - Amerigo Vitagliano
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
| | - Gianluca Raffaello Damiani
- Department of Biomedical Sciences and Human Oncology, University of Bari, 70121 Bari, Italy
- Unit of Obstetrics and Gynecology, University of Bari, Bari, Italy
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5
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Young R, Marinescu P, Seligman N, Adair CD, Hern B. Directional Sensors for Recording Uterine EMG During Pregnancy. Reprod Sci 2023; 30:3190-3196. [PMID: 37217825 DOI: 10.1007/s43032-023-01268-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/10/2023] [Indexed: 05/24/2023]
Abstract
Multichannel uterine electromyography (uEMG) during pregnancy is traditionally performed with electrocardiography (ECG) sensors. Similar signals are often observed in two or more channels, suggesting the ECG sensors report activities originating from the same location on the uterus. To improve signal source localization, we designed a directional sensor or "Area Sensor". Here we compare Area Sensors with ECG sensors for source localization. Subjects were ≥ 38 wks experiencing regular contractions. 6 Area Sensors (n = 8) or 6 to 7 ECG sensors (n = 7) were used to record multichannel uEMG for 60 min. For each sensor type, the similarity of signals observed in pairs of channels during contractions was assessed by quantifying channel crosstalk. Since crosstalk depends on the separation between sensors, analyses were performed within distance groups: A 9-12 cm; B 13-16 cm; C 17-20 cm; D 21-24 cm; E ≥ 25 cm. For ECG sensors, crosstalk was 67.9 ± 14.4% in group A, decreasing to 27.8 ± 17.5% in group E. For Area Sensors, crosstalk was 24.6 ± 18.6% in Group A, decreasing to 12.5 ± 13.8% in group E. Area Sensors showed less crosstalk than ECG sensors in distance groups A, B, C and D, with all p < 0.002. Compared with ECG sensors, Area Sensors are more directional and report uterine activity from a smaller area of the uterine wall. Using 6 Area Sensors separated by at least 17 cm provides acceptably independent multichannel recording. This introduces the possibility of non-invasively evaluating uterine synchronization and the strength of individual uterine contractions in real time.
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Affiliation(s)
| | - Ponnila Marinescu
- Department of Obstetrics and Gynecology, University of Rochester, Rochester, NY, USA
| | - Neil Seligman
- Department of Obstetrics and Gynecology, University of Rochester, Rochester, NY, USA
| | - C David Adair
- Department of Obstetrics and Gynecology, The University of Tennessee College of Medicine, Chattanooga, TN, USA
| | - Braxton Hern
- Vanderbilt University Medical Center, Nashville, TN, USA
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6
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Barnett SD, Asif H, Buxton ILO. Novel identification and modulation of the mechanosensitive Piezo1 channel in human myometrium. J Physiol 2023; 601:1675-1690. [PMID: 35941750 PMCID: PMC9905381 DOI: 10.1113/jp283299] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
Approximately 10% of US births deliver preterm before 37 weeks of completed gestation. Premature infants are at risk for life-long debilitating morbidities and death, and spontaneous preterm labour explains 50% of preterm births. In all cases existing treatments are ineffective, and none are FDA approved. The mechanisms that initiate preterm labour are not well understood but may result from dysfunctional regulation of quiescence mechanisms. Human pregnancy is accompanied by large increases in blood flow, and the uterus must enlarge by orders of magnitude to accommodate the growing fetus. This mechanical strain suggests that stretch-activated channels may constitute a mechanism to explain gestational quiescence. Here we identify for the first time that Piezo1, a mechanosensitive cation channel, is present in the uterine smooth muscle and microvascular endothelium of pregnant myometrium. Piezo is downregulated during preterm labour, and stimulation of myometrial Piezo1 in an organ bath with the agonist Yoda1 relaxes the tissue in a dose-dependent fashion. Further, stimulation of Piezo1 while inhibiting protein kinase A, AKT, or endothelial nitric oxide synthase mutes the negative inotropic effects of Piezo1 activation, intimating that actions on the myocyte and endothelial nitric oxide signalling contribute to Piezo1-mediated contractile dynamics. Taken together, these data highlight the importance of stretch-activated channels in pregnancy maintenance and parturition, and identify Piezo1 as a tocolytic target of interest. KEY POINTS: Spontaneous preterm labour is a serious obstetric dilemma without a known cause or effective treatments. Piezo1 is a stretch-activated channel important to muscle contractile dynamics. Piezo1 is present in the myometrium and is dysregulated in women who experience preterm labour. Activation of Piezo1 by the agonist Yoda1 relaxes the myometrium in a dose-dependent fashion, indicating that Piezo1 modulation may have therapeutic benefits to treat preterm labour.
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Affiliation(s)
- Scott D Barnett
- Department of Pharmacology, Center for Molecular Medicine, Reno School of Medicine, University of Nevada, Reno, NV, USA
| | - Hazik Asif
- Department of Pharmacology, Center for Molecular Medicine, Reno School of Medicine, University of Nevada, Reno, NV, USA
| | - Iain L O Buxton
- Department of Pharmacology, Center for Molecular Medicine, Reno School of Medicine, University of Nevada, Reno, NV, USA
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7
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Wang H, Wen Z, Wu W, Sun Z, Kisrieva-Ware Z, Lin Y, Wang S, Gao H, Xu H, Zhao P, Wang Q, Macones GA, Schwartz AL, Cuculich P, Cahill AG, Wang Y. Noninvasive electromyometrial imaging of human uterine maturation during term labor. Nat Commun 2023; 14:1198. [PMID: 36918533 PMCID: PMC10015052 DOI: 10.1038/s41467-023-36440-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 01/23/2023] [Indexed: 03/16/2023] Open
Abstract
Electromyometrial imaging (EMMI) was recently developed to image the three-dimensional (3D) uterine electrical activation during contractions noninvasively and accurately in sheep. Herein we describe the development and application of a human EMMI system to image and evaluate 3D uterine electrical activation patterns at high spatial and temporal resolution during human term labor. We demonstrate the successful integration of the human EMMI system during subjects' clinical visits to generate noninvasively the uterine surface electrical potential maps, electrograms, and activation sequence through an inverse solution using up to 192 electrodes distributed around the abdomen surface. Quantitative indices, including the uterine activation curve, are developed and defined to characterize uterine surface contraction patterns. We thus show that the human EMMI system can provide detailed 3D images and quantification of uterine contractions as well as novel insights into the role of human uterine maturation during labor progression.
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Affiliation(s)
- Hui Wang
- Department of Physics, Washington University, St. Louis, MO, 63130, USA
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Zichao Wen
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Wenjie Wu
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Biomedical Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Zhexian Sun
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Biomedical Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Zulfia Kisrieva-Ware
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Yiqi Lin
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Electrical and Systems Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Sicheng Wang
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Electrical and Systems Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Hansong Gao
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Electrical and Systems Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Haonan Xu
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Peinan Zhao
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Qing Wang
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - George A Macones
- Department of Women's Health, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Alan L Schwartz
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Phillip Cuculich
- Department of Cardiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Alison G Cahill
- Department of Women's Health, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yong Wang
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO, 63130, USA.
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University, St. Louis, MO, 63130, USA.
- Department of Electrical and Systems Engineering, Washington University, St. Louis, MO, 63130, USA.
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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8
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Monitoring uterine contractions during labor: current challenges and future directions. Am J Obstet Gynecol 2023; 228:S1192-S1208. [PMID: 37164493 DOI: 10.1016/j.ajog.2022.10.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/22/2022] [Accepted: 10/27/2022] [Indexed: 03/21/2023]
Abstract
Organ-level models are used to describe how cellular and tissue-level contractions coalesce into clinically observable uterine contractions. More importantly, these models provide a framework for evaluating the many different contraction patterns observed in laboring patients, ideally offering insight into the pitfalls of currently available recording modalities and suggesting new directions for improving recording and interpretation of uterine contractions. Early models proposed wave-like propagation of bioelectrical activity as the sole mechanism for recruiting the myometrium to participate in the contraction and increase contraction strength. However, as these models were tested, the results consistently revealed that sequentially propagating waves do not travel long distances and do not encompass the gravid uterus. To resolve this discrepancy, a model using 2 mechanisms, or a "dual model," for organ-level signaling has been proposed. In the dual model, the myometrium is recruited by action potentials that propagate wave-like as far as 10 cm. At longer distances, the myometrium is recruited by a mechanotransduction mechanism that is triggered by rising intrauterine pressure. In this review, we present the influential models of uterine function, highlighting their main features and inconsistencies, and detail the role of intrauterine pressure in signaling and cervical dilation. Clinical correlations demonstrate the application of organ-level models. The potential to improve the recording and clinical interpretation of uterine contractions when evaluating labor is discussed, with emphasis on uterine electromyography. Finally, 7 questions are posed to help guide future investigations on organ-level signaling mechanisms.
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9
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Wang Y, Li X, Wei N, Liu Y, Liu X, Sun R, Huang C, Yao B, Wang H. Automated measurement of endometrial peristalsis in cine transvaginal ultrasound images. Front Physiol 2022; 13:983177. [PMID: 36187777 PMCID: PMC9523211 DOI: 10.3389/fphys.2022.983177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/02/2022] [Indexed: 11/13/2022] Open
Abstract
Objectives: Endometrial peristalsis (EP) in non-pregnant uterine can be assessed by visual assessment of transvaginal ultrasound (TVUS). However, visual assessment is subjective, and the outcome depends on the sonographers and video analysts. This study aimed to create a newly developed automatic analysis algorithm for measuring the EP compared to visual assessment.Methods: A retrospective analysis was performed using the datasets from in vitro fertilization and embryo transfer (IVF-ET), who underwent the evaluation of EP by TVUS within 5 days prior to transplantation. 158 cine TVUS images were used to develop the automated analysis algorithm, and 37 cine TVUS images were evaluated by both visual and automated analysis algorithms. The algorithm was developed by applying the optical flow technology and enabled objective analysis of the number, direction, and intensity of EP.Results: The number of peristaltic waves counted by visual assessment was 4.2 ± 2.3 (mean ± standard deviation) and 4.1 ± 2.1 for doctors one and two, respectively. The number of waves counted with the algorithm was 3.6 ± 2.1 at first evaluation and 3.7 ± 2.0 at repeated evaluation. A significant difference was found between the algorithm count and visual assessment (p = 0.001, 0.002, 0.003, 0.008). The ICC values for algorithm versus manuals ranged from 0.84 to 0.96 and 0.87 to 0.96. The numbers of the cervix-to-fundus (CF), fundus-to-cervix (FC), and both cervix-to-fundal and fundus-to-cervix (CF + FC) directions of EP counted by the algorithm were 50, 52, and 32, respectively. The numbers counted by visual assessment were 43, 45, and 46, respectively. The number of EP was the same in 87% of the two algorithm counts. The number was lower between the algorithm and visual analysis (79% with complete agreement). The EP intensity assessed by the algorithm was 2.6 ± 1.1, and the peristalsis velocity was 0.147 (0.07) mm/s.Conclusion: The fully automated analysis algorithm can be used to quantify uterine peristalsis comparable to visual assessment.
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Affiliation(s)
- Yue Wang
- Department of Ultrasound, Peking University Shenzhen Hospital, Shenzhen, China
| | - Xiaokun Li
- Department of Ultrasound, Peking University Shenzhen Hospital, Shenzhen, China
| | - Niya Wei
- Department of Ultrasound, Peking University Shenzhen Hospital, Shenzhen, China
| | - Yuanxi Liu
- Shenzhen Wisonic Medical Technology Co., Ltd., Shenzhen, China
| | - Xinting Liu
- Department of Ultrasound, Peking University Shenzhen Hospital, Shenzhen, China
| | - Ruijie Sun
- Department of Ultrasound, Peking University Shenzhen Hospital, Shenzhen, China
| | - Chan Huang
- Shenzhen Wisonic Medical Technology Co., Ltd., Shenzhen, China
| | - Bin Yao
- Shenzhen Wisonic Medical Technology Co., Ltd., Shenzhen, China
| | - Huifang Wang
- Department of Ultrasound, Peking University Shenzhen Hospital, Shenzhen, China
- *Correspondence: Huifang Wang,
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10
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Quinn MJ. Physiological approaches to reducing blood loss during cesarean delivery. Am J Obstet Gynecol 2022; 226:868-869. [PMID: 35065942 DOI: 10.1016/j.ajog.2022.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 01/14/2022] [Indexed: 11/30/2022]
Affiliation(s)
- M J Quinn
- Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University, 910 Hengshan Rd., Xujiahui, Shanghai, China 200030.
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11
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On the effect of irregular uterine activity during a vaginal delivery using an electro-chemo-mechanical constitutive model. J Mech Behav Biomed Mater 2022; 131:105250. [DOI: 10.1016/j.jmbbm.2022.105250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/08/2022] [Accepted: 04/17/2022] [Indexed: 11/21/2022]
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12
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Marinescu PS, Young RC, Miller LA, Llop JR, Pressman EK, Seligman NS. Mid-trimester uterine electromyography in patients with a short cervix. Am J Obstet Gynecol 2022; 227:83.e1-83.e17. [PMID: 35351409 DOI: 10.1016/j.ajog.2022.03.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/08/2022] [Accepted: 03/22/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND Preterm birth is the largest single cause of infant death in the United States. A cervical length of <2.5 cm, measured in the mid-trimester, has been shown to identify individuals at increased risk. Uterine electromyography is an emerging technology for noninvasively assessing uterine bioelectrical activity. With its ability to characterize nuanced differences in myometrial signals, uterine electromyography assessments during the mid-trimester may provide insight into the mechanisms of cervical shortening. OBJECTIVE This study aimed to characterize uterine bioelectrical activity in pregnant individuals with short cervices in the mid-trimester compared with that of pregnant individuals of the same gestational age with normal cervical lengths. STUDY DESIGN This is a prospective cohort study of subjects with singleton, nonanomalous pregnancies between 16 weeks and 0 days and 22 weeks and 6 days of gestational age. Subjects with normal cervical length (≥3.0 cm) were compared with subjects with short cervical length (<2.5 cm). The short-cervical-length cohort was further stratified by history of preterm birth. Multichannel uterine electromyography recordings were obtained for ∼60 minutes using proprietary, directional electromyography sensors on the abdomen. Uterine electromyography signals were observed and classified in groups as spikes, short bursts, and bursts. Primary outcomes were relative expression of spike, short-burst, and burst uterine electromyography signals. Subgroup analyses assessed each signal percentage by cervical length, history of preterm birth, and gestational age at delivery. Differences in percentage of uterine electromyography signals according to cervical length were analyzed using nonparametric tests of significance. RESULTS Of the 28 included subjects, 10 had normal and 18 had short cervical length. There were 9 subjects with short cervical length and a history of preterm birth. Spikes were the most commonly recorded signals and were higher in the normal-cervical-length cohort (96.3% [interquartile range, 93.1%-100.0%]) than the short-cervical-length cohort (75.2% [interquartile range, 66.7%-92.0%], P=.001). In contrast, median percentages of short-bursts and bursts were significantly higher in subjects with a short cervical length (17.3% [interquartile range, 13.6%-23.9%] vs 2.5% for normal cervical length [interquartile range, 0%-5.5%], P=.001 and 6.6% [interquartile range, 0%-13.4%] vs 0% for normal cervical length [interquartile range, 0%-2.8%], P=.014, respectively). Within subgroup analyses, cervical length was inversely proportional to percentage of observed short-bursts (P=.013) and bursts (P=.014). Subjects with short cervical length and history of preterm birth had higher burst percentages (12.8% [interquartile range, 9.0%-15.7%]) than those with short cervical length and no history of preterm birth (3.3% [interquartile range, 0%-5.0%], P=.003). CONCLUSION Short-burst and burst uterine electromyography signals are observed more frequently in mid-trimester patients with short cervical lengths. This relationship provides insight into abnormal myometrial activation in the mid-trimester and offers a plausible biophysiological link to cervical shortening.
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13
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Malik M, Roh M, England SK. Uterine contractions in rodent models and humans. Acta Physiol (Oxf) 2021; 231:e13607. [PMID: 33337577 PMCID: PMC8047897 DOI: 10.1111/apha.13607] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/18/2022]
Abstract
Aberrant uterine contractions can lead to preterm birth and other labour complications and are a significant cause of maternal morbidity and mortality. To investigate the mechanisms underlying dysfunctional uterine contractions, researchers have used experimentally tractable small animal models. However, biological differences between humans and rodents change how researchers select their animal model and interpret their results. Here, we provide a general review of studies of uterine excitation and contractions in mice, rats, guinea pigs, and humans, in an effort to introduce new researchers to the field and help in the design and interpretation of experiments in rodent models.
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Affiliation(s)
- Manasi Malik
- Center for Reproductive Health SciencesDepartment of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMOUSA
| | - Michelle Roh
- Center for Reproductive Health SciencesDepartment of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMOUSA
| | - Sarah K. England
- Center for Reproductive Health SciencesDepartment of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMOUSA
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14
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Muñoz-Pérez VM, Ortiz MI, Salas-Casa A, Pérez-Guerrero J, Castillo-Pacheco N, Barragán-Ramírez G, Hernándes-Alejandro M. In vitro effects of citral on the human myometrium: Potential adjunct therapy to prevent preterm births. Birth Defects Res 2021; 113:613-622. [PMID: 33484091 DOI: 10.1002/bdr2.1873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 01/09/2021] [Accepted: 01/12/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND Premature infants contribute to infant morbidity and mortality especially in low resource settings. Information on tocolytic and/or anti-inflammatory effects of several plant extracts, such as citral, could help prevent preterm birth cases and reduce the number of preterm infants. The aim of this study was to evaluate the in vitro tocolytic and anti-inflammatory effect of citral on myometrial tissues of the human uterus. METHODS Myometrial samples from uteri obtained after hysterectomy were used in functional tests to evaluate the inhibitory effect of citral on PGF-2α induced contractions. The intracellular cyclic adenosine monophosphate (cAMP) levels generated in response to citral in human myometrial homogenates were measured by ELISAs. Forskolin was used as a positive control. The anti-inflammatory effect of citral was determined through the measurement of two pro-inflammatory cytokines, tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, and the anti-inflammatory cytokine IL-10, in human myometrial explants stimulated with lipopolysaccharide (LPS). RESULTS Citral was able to induce a significant inhibition of PGF-2α induced contractions at the highest concentration level (p < .05). Citral caused a concentration-dependent increase in myometrial cAMP levels (p < .05) and a concentration-dependent decrease in LPS-induced TNFα and IL-1β production, while IL-10 production increased significantly (p < .05). The anti-inflammatory and tocolytic effects induced by citral could be associated with an increase in cAMP levels in human myometrial samples. CONCLUSION These properties place citral as a potentially safe and effective adjuvant agent in preterm birth cases, an obstetric and gynecological problem that requires urgent attention.
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Affiliation(s)
- Víctor Manuel Muñoz-Pérez
- Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca, Mexico
| | - Mario I Ortiz
- Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca, Mexico
| | - Andrés Salas-Casa
- Área Académica de Gerontología del Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca, Mexico
| | - Jessica Pérez-Guerrero
- Departamento de Ginecología y Obstetricia del Hospital General de los SSH, Pachuca, Mexico
| | - Narmi Castillo-Pacheco
- Departamento de Ginecología y Obstetricia del Hospital General de los SSH, Pachuca, Mexico
| | | | - Mario Hernándes-Alejandro
- Departamento de Bioingeniería, Unidad profesional Interdisciplinaria de biotecnología del Instituto Politécnico Nacional (UPIBI-IPN), México City, Mexico
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15
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Ince O, Karaca SY, Karaca I. M-mode Ultrasound Scan as a Potential Alternative Technique for Monitoring Uterine Contractions in Obese Patients. Reprod Sci 2021; 28:1989-1995. [PMID: 33442847 DOI: 10.1007/s43032-020-00435-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/13/2020] [Indexed: 11/29/2022]
Abstract
We investigate motion mode (M-mode) ultrasound scan as a potential non-invasive uterine monitoring technique and compare its contraction characteristics with external tocodynamometry (TOCO). This prospective diagnostic accuracy study included 39 term pregnant woman in active spontaneous labor. M-mode and TOCO were simultaneously performed and uterine contraction characteristics and consistency were compared quantitatively and visually. The results identified a 71.5% ± 35.3% uterine wall thickening during uterine contractions on M-mode. Uterine monitoring with M-mode had a consistency rate of 88.7% ± 6.9% with conventional TOCO method. During 20-min monitoring, the number of detected contractions was significantly higher (p < 0.001) in M-mode (8.2 ± 1.2) than TOCO (7.4 ± 1.5). As for the mean value of the duration of a contraction (seconds), it was significantly shorter (p < 0.001) in M-mode (38.5 ± 3.5) than TOCO (49.2 ± 4.1). For M-mode, the number of detected contractions had a negative but insignificant correlation with the body mass index (BMI) (r = - 0.25 [- 0.52, 0.07], p = 0.127) and the subcutaneous tissue thickness (STT) (r = - 0.21 [- 0.49, 0.11], p = 0.200). As for TOCO, the contractions had a negative and significant correlation with BMI (r = - 0.41 [- 0.64, - 0.11], p = 0.009) and negative and insignificant correlation with STT (r = - 0.26 [- 0.54, 0.06], p = 0.104). The evidence suggests that contraction detection with M-mode is a promising non-invasive technique for uterine monitoring. The preliminary analysis finds that contraction detection is not affected by BMI or STT. With future sensitivity studies, and improvements in image-processing and software technologies, the proposed technique promises to be a viable alternative to existing techniques, especially for obese patients.
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Affiliation(s)
- Onur Ince
- Department of Obstetrics and Gynaecology, Kutahya Health Sciences University, 43000, Kutahya, Turkey.,Department of Statistics, Faculty of Arts and Science, Middle East Technical University, 06800, Ankara, Turkey
| | - Suna Yildirim Karaca
- Department of Obstetrics and Gynaecology, Health Sciences University Tepecik Education and Research Hospital, 35020, Izmir, Turkey
| | - Ibrahim Karaca
- Department of Obstetrics and Gynaecology, Bakirkoy Dr. Sadi Konuk Training and Research Hospital, 34147, Istanbul, Turkey.
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Grimm MJ. Forces Involved with Labor and Delivery-A Biomechanical Perspective. Ann Biomed Eng 2021; 49:1819-1835. [PMID: 33432512 DOI: 10.1007/s10439-020-02718-3] [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: 11/01/2020] [Accepted: 12/25/2020] [Indexed: 12/20/2022]
Abstract
Childbirth is a primarily biomechanical process of physiology, and one that engineers have recently begun to address in a broader fashion. Computational models are being developed to address the biomechanical effects of parturition on both maternal and fetal tissues. Experimental research is being conducted to understand how maternal tissues adapt to intrauterine forces near the onset of labor. All of this research requires an understanding of the forces that are developed through maternal efforts-both uterine contractions and semi-voluntary pushing-and that can be applied by the clinician to assist with the delivery. This work reviews the current state of knowledge regarding forces of labor and delivery, with a focus on macro-level biomechanics.
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Affiliation(s)
- Michele J Grimm
- Departments of Mechanical Engineering and Biomedical Engineering, Michigan State University, 428 S. Shaw Lane, East Lansing, MI, 48824, USA.
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17
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Wray S, Arrowsmith S. Uterine Excitability and Ion Channels and Their Changes with Gestation and Hormonal Environment. Annu Rev Physiol 2020; 83:331-357. [PMID: 33158376 DOI: 10.1146/annurev-physiol-032420-035509] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We address advances in the understanding of myometrial physiology, focusing on excitation and the effects of gestation on ion channels and their relevance to labor. This review moves through pioneering studies to exciting new findings. We begin with the myometrium and its myocytes and describe how excitation might initiate and spread in this myogenic smooth muscle. We then review each of the ion channels in the myometrium: L- and T-type Ca2+ channels, KATP (Kir6) channels, voltage-dependent K channels (Kv4, Kv7, and Kv11), twin-pore domain K channels (TASK, TREK), inward rectifier Kir7.1, Ca2+-activated K+ channels with large (KCNMA1, Slo1), small (KCNN1-3), and intermediate (KCNN4) conductance, Na-activated K channels (Slo2), voltage-gated (SCN) Na+ and Na+ leak channels, nonselective (NALCN) channels, the Na K-ATPase, and hyperpolarization-activated cation channels. We finish by assessing how three key hormones- oxytocin, estrogen, and progesterone-modulate and integrate excitability throughout gestation.
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Affiliation(s)
- Susan Wray
- Department of Women's and Children's Health, University of Liverpool, Liverpool L69 3BX, United Kingdom;
| | - Sarah Arrowsmith
- Department of Women's and Children's Health, University of Liverpool, Liverpool L69 3BX, United Kingdom;
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18
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Garfield RE, Murphy L, Gray K, Towe B. Review and Study of Uterine Bioelectrical Waveforms and Vector Analysis to Identify Electrical and Mechanosensitive Transduction Control Mechanisms During Labor in Pregnant Patients. Reprod Sci 2020; 28:838-856. [PMID: 33090378 DOI: 10.1007/s43032-020-00358-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/11/2020] [Indexed: 12/15/2022]
Abstract
The bioelectrical signals that produce uterine contractions during parturition are not completely understood. The objectives are as follows: (1) to review the literature and information concerning uterine biopotential waveforms generated by the uterus, known to produce contractions, and evaluate mechanotransduction in pregnant patients using electromyographic (EMG) recording methods and (2) to study a new approach, uterine vector analysis, commonly used for the heart: vectorcardiography analysis. The patients used in this study were as follows: (1) patients at term not in labor (n = 3); (2) patients during the 1st stage of labor at cervical dilations from 2 to 10 cm (n = 30); and (3) patients in the 2nd stage of labor and during delivery (n = 3). We used DC-coupled electrodes and PowerLab hardware (model no. PL2604, ADInstruments, Castle Hill, Australia), with software (LabChart, ADInstruments) for storage and analysis of biopotentials. Uterine and abdominal EMG recordings were made from the surface of each patient using 3 electrode pairs with 1 pair (+ and -, with a 31-cm spacing distance) placed in the right/left position (X position) and with 1 pair placed in an up/down position (Y position, also 31 cm apart) and with the third pair at the front/back (Z position). Using signals from the three X, Y, and Z electrodes, slow (0.03 to 0.1 Hz, high amplitude) and fast wave (0.3 to 1 Hz, low amplitude) biopotentials were recorded. The amplitudes of the slow waves and fast waves were significantly higher during the 2nd stage of labor compared to the 1st stage (respectively, p = 9.54 × e-3 and p = 3.94 × e-7). When 2 channels were used, for example, the X vs. Y, for 2-D vector analysis or 3 channels, X vs. Y vs. Z, for 3-D analysis, are plotted against each other on their axes, this produces a vector electromyometriogram (EMMG) that shows no directionality for fast waves and a downward direction for slow waves. Similarly, during the 2nd stage of labor during abdominal contractions ("pushing"), the slow and fast waves were enlarged. Manual applied pressure was used to evoke bioelectrical activity to examine the mechanosensitivity of the uterus. Conclusions: (1) Phasic contractility of the uterus is a product of slow waves and groups of fast waves (bursts of spikes) to produce myometrial contractile responses. (2) 2-D and 3-D uterine vector analyses (uterine vector electromyometriogram) demonstrate no directionality of small fast waves while the larger slow waves represent the downward direction of biopotentials towards the cervical opening. (3) Myometrial cell action event excitability and subsequent contractility likely amplify slow wave activity input and uterine muscle contractility via mechanotransduction systems. (4) Models illustrate the possible relationships of slow to fast waves and the association of a mechanotransduction system and pacemaker activity as observed for slow waves and pacemakers in gastrointestinal muscle. (5) The interaction of these systems is thought to regulate uterine contractility. (6) This study suggests a potential indicator of delivery time. Such vector approaches might help us predict the progress of gestation and better estimate the timing of delivery, gestational pathologies reflected in bioelectric events, and perhaps the potential for premature delivery drug and mechanical interventions.
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Affiliation(s)
- R E Garfield
- Department of Obstetrics and Gynecology, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.
| | - Lauren Murphy
- Department of Obstetrics and Gynecology, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Kendra Gray
- Department of Obstetrics and Gynecology, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Bruce Towe
- Department of Biomedical Engineering, Arizona State University, Tempe, AZ, USA
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Abstract
Contractions are produced through a complex interplay of hormonal, mechanical, and electrical factors. In labor, contractions are measured using the Montevideo unit. Clinical considerations in labor wherein contraction assessment becomes paramount include the care of women whose labor is complicated by abnormal progress or tachysystole. In an era of obstetrics in which the high cesarean rate is a major issue of concern, there remain many questions as to how to best incorporate contraction monitoring into practice in order to optimize care. Technological advancement has led to the development on new modalities that can be used to study contraction physiology, and there may be an opportunity in the future to apply these methods for use in the clinical setting. This article also makes a case for the need to reevaluate the current measures of uterine contractile activity and the definition of contraction adequacy using updated definitions of normal labor progress.
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Affiliation(s)
- Stephen E Gee
- Department of Obstetrics & Gynecology, The Ohio State University College of Medicine, 395 W. 12th Ave, 5th floor, 43210 Columbus, OH, United States.
| | - Heather A Frey
- Department of Obstetrics & Gynecology, The Ohio State University College of Medicine, 395 W. 12th Ave, 5th floor, 43210 Columbus, OH, United States
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20
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Wu W, Wang H, Zhao P, Talcott M, Lai S, McKinstry RC, Woodard PK, Macones GA, Schwartz AL, Cahill AG, Cuculich PS, Wang Y. Noninvasive high-resolution electromyometrial imaging of uterine contractions in a translational sheep model. Sci Transl Med 2020; 11:11/483/eaau1428. [PMID: 30867320 DOI: 10.1126/scitranslmed.aau1428] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/09/2018] [Accepted: 02/20/2019] [Indexed: 12/20/2022]
Abstract
In current clinical practice, uterine contractions are monitored via a tocodynamometer or an intrauterine pressure catheter, both of which provide crude information about contractions. Although electrohysterography/electromyography can measure uterine electrical activity, this method lacks spatial specificity and thus cannot accurately measure the exact location of electrical initiation and location-specific propagation patterns of uterine contractions. To comprehensively evaluate three-dimensional uterine electrical activation patterns, we describe here the development of electromyometrial imaging (EMMI) to display the three-dimensional uterine contractions at high spatial and temporal resolution. EMMI combines detailed body surface electrical recording with body-uterus geometry derived from magnetic resonance images. We used a sheep model to show that EMMI can reconstruct uterine electrical activation patterns from electrodes placed on the abdomen. These patterns closely match those measured with electrodes placed directly on the uterine surface. In addition, modeling experiments showed that EMMI reconstructions are minimally affected by noise and geometrical deformation. Last, we show that EMMI can be used to noninvasively measure uterine contractions in sheep in the same setup as would be used in humans. Our results indicate that EMMI can noninvasively, safely, accurately, robustly, and feasibly image three-dimensional uterine electrical activation during contractions in sheep and suggest that similar results might be obtained in clinical setting.
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Affiliation(s)
- Wenjie Wu
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.,Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA.,Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hui Wang
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.,Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Department of Physics, Washington University, St. Louis, MO 63110, USA
| | - Peinan Zhao
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael Talcott
- Division of Comparative Medicine, Washington University, St. Louis, MO 63110, USA
| | - Shengsheng Lai
- Department of Medical Devices, Guangdong Food and Drug Vocational College, Guangzhou, Guangdong Province, P.R. China
| | - Robert C McKinstry
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Pamela K Woodard
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - George A Macones
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alan L Schwartz
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alison G Cahill
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Phillip S Cuculich
- Department of Cardiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Yong Wang
- Center for Reproductive Health Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA. .,Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA.,Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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22
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Saleem S, Saeed A, Usman S, Ferzund J, Arshad J, Mirza J, Manzoor T. Granger causal analysis of electrohysterographic and tocographic recordings for classification of term vs. preterm births. Biocybern Biomed Eng 2020. [DOI: 10.1016/j.bbe.2020.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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23
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Hulls CM, Lentle RG, Chua WH, Suisted P, King QM, Chagas JAB, Chambers JP, Stewart L. Spatiotemporal Mapping of the Contracting Gravid Uterus of the Rabbit Shows Contrary Changes With Increasing Gestation and Dosage With Oxytocin. Front Endocrinol (Lausanne) 2019; 10:802. [PMID: 31824420 PMCID: PMC6882407 DOI: 10.3389/fendo.2019.00802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022] Open
Abstract
Spontaneous and oxytocin induced contractile activity was quantified in the bicornuate uteri of pregnant rabbits maintained in situ, using data from two- and uni- dimensional video spatiotemporal maps (VSTM) of linear and area strain rate and compared statistically. Spontaneous contractions occurred over a range of frequencies between 0.1 and 10 cpm, in gravid animals at 18-21 and at 28 days of gestation, and propagated both radially and longitudinally over the uterine wall overlying each fetus. Patches of contractions were randomly distributed over the entire surface of the cornua and were pleomorphic in shape. No spatial coordination was evident between longitudinal and circular muscle layers nor temporal coordination that could indicate the activity of a localized pacemaker. The density and duration of contractions decreased, and their frequency increased with the length of gestation in the non-laboring uterus. Increasing intravenous doses of oxytocin had no effect on the mean frequencies, or the mean durations of contractions in rabbits of 18-21 days gestation, but caused frequencies to decrease and durations to increase in rabbits of 28 days gestation, from greater spatial and temporal clustering of individual contractions. This was accompanied by an increase in the distance of propagation, the mean size of the patches of contraction, the area of the largest patch of contraction and the overall density of patches. Together these results suggest that progressive smooth muscle hypertrophy and displacement with increasing gestation is accompanied by a decrease in smooth muscle connectivity causing an increase in wall compliance and that oxytocin restores connectivity and decreases compliance, promoting volumetric expulsion rather than direct propulsion of the fetus by peristalsis. The latter effects were reversed by the β2 adrenergic receptor agonist salbutamol thus reducing area of contraction, and the duration and distance of propagation.
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Affiliation(s)
- Corrin M. Hulls
- Medical Physiology Research Unit, School of Health Sciences, College of Health, Massey University, Palmerston North, New Zealand
| | - Roger G. Lentle
- Medical Physiology Research Unit, School of Health Sciences, College of Health, Massey University, Palmerston North, New Zealand
| | - Wei-Hang Chua
- Medical Physiology Research Unit, School of Health Sciences, College of Health, Massey University, Palmerston North, New Zealand
| | - Philip Suisted
- Division of Obstetrics and Gynaecology, Palmerston North Hospital, Palmerston North, New Zealand
| | - Quinten M. King
- Division of Urology, Palmerston North Hospital, Palmerston North, New Zealand
| | - Joana A. B. Chagas
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - John P. Chambers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Lauren Stewart
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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24
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Huber C, Shazly SA, Ruano R. Potential use of electrohysterography in obstetrics: a review article. J Matern Fetal Neonatal Med 2019; 34:1666-1672. [PMID: 31303075 DOI: 10.1080/14767058.2019.1639663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Monitoring the uterine contraction during pregnancy is necessary to monitor labor progress, fetal and maternal well-being, and uterine activity. The aim of this review was to evaluate the performance of electrohysterography and to analyze the nature of uterine contraction. A search was undertaken using PubMed, Embase, and ClinicalTrials.gov database from 1 January 1950 to 1 November 2018. Search terms include: "Uterine" or "Uterus" or "Labor" or "Labour" and "electrical activity" or "electrohysterogram" or "electrohysterograph". Reviewing the literature, electrohysterography showed a higher sensitivity for uterine contraction detection and was independent of body mass index, abdominal wall thickness, or maternal position enabling monitoring obese patients as well. Electrohysterography can enhance uterine monitoring throughout labor because of its noninvasiveness, adhesive properties, and reduced obesity sensitiveness. Electrohysterography should be available to safely improve intrapartum monitoring instead of the invasive intrauterine pressure catheter.
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Affiliation(s)
- Carola Huber
- Department of Obstetrics and Gynaecology, Division of Maternal-Fetal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Sherif A Shazly
- Department of Obstetrics and Gynaecology, Division of Maternal-Fetal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Rodrigo Ruano
- Department of Obstetrics and Gynaecology, Division of Maternal-Fetal Medicine, Mayo Clinic, Rochester, MN, USA
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25
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The Myometrium: From Excitation to Contractions and Labour. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1124:233-263. [PMID: 31183830 DOI: 10.1007/978-981-13-5895-1_10] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
We start by describing the functions of the uterus, its structure, both gross and fine, innervation and blood supply. It is interesting to note the diversity of the female's reproductive tract between species and to remember it when working with different animal models. Myocytes are the overwhelming cell type of the uterus (>95%) and our focus. Their function is to contract, and they have an intrinsic pacemaker and rhythmicity, which is modified by hormones, stretch, paracrine factors and the extracellular environment. We discuss evidence or not for pacemaker cells in the uterus. We also describe the sarcoplasmic reticulum (SR) in some detail, as it is relevant to calcium signalling and excitability. Ion channels, including store-operated ones, their contributions to excitability and action potentials, are covered. The main pathway to excitation is from depolarisation opening voltage-gated Ca2+ channels. Much of what happens downstream of excitability is common to other smooth muscles, with force depending upon the balance of myosin light kinase and phosphatase. Mechanisms of maintaining Ca2+ balance within the myocytes are discussed. Metabolism, and how it is intertwined with activity, blood flow and pH, is covered. Growth of the myometrium and changes in contractile proteins with pregnancy and parturition are also detailed. We finish with a description of uterine activity and why it is important, covering progression to labour as well as preterm and dysfunctional labours. We conclude by highlighting progress made and where further efforts are required.
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26
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Loppini A, Gizzi A, Ruiz-Baier R, Cherubini C, Fenton FH, Filippi S. Competing Mechanisms of Stress-Assisted Diffusivity and Stretch-Activated Currents in Cardiac Electromechanics. Front Physiol 2018; 9:1714. [PMID: 30559677 PMCID: PMC6287028 DOI: 10.3389/fphys.2018.01714] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 11/14/2018] [Indexed: 12/13/2022] Open
Abstract
We numerically investigate the role of mechanical stress in modifying the conductivity properties of cardiac tissue, and also assess the impact of these effects in the solutions generated by computational models for cardiac electromechanics. We follow the recent theoretical framework from Cherubini et al. (2017), proposed in the context of general reaction-diffusion-mechanics systems emerging from multiphysics continuum mechanics and finite elasticity. In the present study, the adapted models are compared against preliminary experimental data of pig right ventricle fluorescence optical mapping. These data contribute to the characterization of the observed inhomogeneity and anisotropy properties that result from mechanical deformation. Our novel approach simultaneously incorporates two mechanisms for mechano-electric feedback (MEF): stretch-activated currents (SAC) and stress-assisted diffusion (SAD); and we also identify their influence into the nonlinear spatiotemporal dynamics. It is found that (i) only specific combinations of the two MEF effects allow proper conduction velocity measurement; (ii) expected heterogeneities and anisotropies are obtained via the novel stress-assisted diffusion mechanisms; (iii) spiral wave meandering and drifting is highly mediated by the applied mechanical loading. We provide an analysis of the intrinsic structure of the nonlinear coupling mechanisms using computational tests conducted with finite element methods. In particular, we compare static and dynamic deformation regimes in the onset of cardiac arrhythmias and address other potential biomedical applications.
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Affiliation(s)
- Alessandro Loppini
- Unit of Nonlinear Physics and Mathematical Modeling, Department of Engineering, University Campus Bio-Medico of Rome, Rome, Italy
| | - Alessio Gizzi
- Unit of Nonlinear Physics and Mathematical Modeling, Department of Engineering, University Campus Bio-Medico of Rome, Rome, Italy
| | - Ricardo Ruiz-Baier
- Mathematical Institute, University of Oxford, Oxford, United Kingdom.,Laboratory of Mathematical Modelling, Institute of Personalized Medicine, Sechenov University, Moscow, Russia
| | - Christian Cherubini
- Unit of Nonlinear Physics and Mathematical Modeling, Department of Engineering, University Campus Bio-Medico of Rome, Rome, Italy.,ICRANet, Pescara, Italy
| | - Flavio H Fenton
- Georgia Institute of Technology, School of Physics, Atlanta, GA, United States
| | - Simonetta Filippi
- Unit of Nonlinear Physics and Mathematical Modeling, Department of Engineering, University Campus Bio-Medico of Rome, Rome, Italy.,ICRANet, Pescara, Italy
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27
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Changes in Intra-Amniotic, Fetal Intrathoracic, and Intraperitoneal Pressures with Uterine Contraction: A Report of Three Cases. Case Rep Obstet Gynecol 2018; 2018:4281528. [PMID: 30298111 PMCID: PMC6157181 DOI: 10.1155/2018/4281528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/07/2018] [Accepted: 08/16/2018] [Indexed: 11/22/2022] Open
Abstract
Intra-amniotic, fetal intrathoracic, and intraperitoneal pressures during pregnancy have been previously investigated. However, to our knowledge, changes in these pressures during uterine contractions have not been reported. Herein, we present three cases of polyhydramnios, fetal pleural effusion, and fetal ascites, in which intra-amniotic, fetal intrathoracic, intraperitoneal pressures increased with uterine contractions. These pressure increases may affect the fetal circulation. We suggest that managing potential premature delivery (e.g., with tocolysis) is important in cases with polyhydramnios and excess fluid in fetal body areas, such as the thorax, abdomen, and heart. The results of this preliminary study on intrafetal pressure measurements will be useful in performing fetal and neonatal surgeries in the future.
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28
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Zhang M, La Rosa PS, Eswaran H, Nehorai A. Estimating uterine source current during contractions using magnetomyography measurements. PLoS One 2018; 13:e0202184. [PMID: 30138376 PMCID: PMC6121809 DOI: 10.1371/journal.pone.0202184] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 05/29/2018] [Indexed: 11/28/2022] Open
Abstract
Understanding the uterine source of the electrophysiological activity of
contractions during pregnancy is of scientific interest and potential clinical
applications. In this work, we propose a method to estimate uterine source
currents from magnetomyography (MMG) temporal course measurements on the
abdominal surface. In particular, we develop a linear forward model, based on
the quasistatic Maxwell’s equations and a realistic four-compartment volume
conductor, relating the magnetic fields to the source currents on the uterine
surface through a lead-field matrix. To compute the lead-field matrix, we use a
finite element method that considers the anisotropic property of the myometrium.
We estimate the source currents by minimizing a constrained least-squares
problem to solve the non-uniqueness issue of the inverse problem. Because we
lack the ground truth of the source current, we propose to predict the
intrauterine pressure from our estimated source currents by using an
absolute-value-based method and compare the result with real abdominal
deflection recorded during contractile activity. We test the feasibility of the
lead-field matrix by displaying the lead fields that are generated by putative
source currents at different locations in the myometrium: cervix and fundus,
left and right, front and back. We then illustrate our method by using three
synthetic MMG data sets, which are generated using our previously developed
multiscale model of uterine contractions, and three real MMG data sets, one of
which has simultaneous real abdominal deflection measurements. The numerical
results demonstrate the ability of our method to capture the local contractile
activity of human uterus during pregnancy. Moreover, the predicted intrauterine
pressure is in fair agreement with the real abdominal deflection with respect to
the timing of uterine contractions.
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Affiliation(s)
- Mengxue Zhang
- Preston M. Green Department of Electrical and Systems Engineering,
Washington University in Saint Louis, Saint Louis, Missouri, United States of
America
| | - Patricio S. La Rosa
- Geospatial Analytics, Global IT Analytics, Monsanto Company, Saint Louis,
Missouri, United States of America
| | - Hari Eswaran
- Department of Obstetrics and Gynecology, University of Arkansas for
Medical Sciences, Little Rock, Arkansas, United States of America
| | - Arye Nehorai
- Preston M. Green Department of Electrical and Systems Engineering,
Washington University in Saint Louis, Saint Louis, Missouri, United States of
America
- * E-mail:
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29
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Young RC. The uterine pacemaker of labor. Best Pract Res Clin Obstet Gynaecol 2018; 52:68-87. [PMID: 29866432 DOI: 10.1016/j.bpobgyn.2018.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 04/10/2018] [Indexed: 10/17/2022]
Abstract
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.
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30
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Yochum M, Laforêt J, Marque C. Multi-scale and multi-physics model of the uterine smooth muscle with mechanotransduction. Comput Biol Med 2017; 93:17-30. [PMID: 29253628 DOI: 10.1016/j.compbiomed.2017.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 12/02/2017] [Accepted: 12/02/2017] [Indexed: 11/18/2022]
Abstract
Preterm labor is an important public health problem. However, the efficiency of the uterine muscle during labor is complex and still poorly understood. This work is a first step towards a model of the uterine muscle, including its electrical and mechanical components, to reach a better understanding of the uterus synchronization. This model is proposed to investigate, by simulation, the possible role of mechanotransduction for the global synchronization of the uterus. The electrical diffusion indeed explains the local propagation of contractile activity, while the tissue stretching may play a role in the synchronization of distant parts of the uterine muscle. This work proposes a multi-physics (electrical, mechanical) and multi-scales (cell, tissue, whole uterus) model, which is applied to a realistic uterus 3D mesh. This model includes electrical components at different scales: generation of action potentials at the cell level, electrical diffusion at the tissue level. It then links these electrical events to the mechanical behavior, at the cellular level (via the intracellular calcium concentration), by simulating the force generated by each active cell. It thus computes an estimation of the intra uterine pressure (IUP) by integrating the forces generated by each active cell at the whole uterine level, as well as the stretching of the tissue (by using a viscoelastic law for the behavior of the tissue). It finally includes at the cellular level stretch activated channels (SACs) that permit to create a loop between the mechanical and the electrical behavior (mechanotransduction). The simulation of different activated regions of the uterus, which in this first "proof of concept" case are electrically isolated, permits the activation of inactive regions through the stretching (induced by the electrically active regions) computed at the whole organ scale. This permits us to evidence the role of the mechanotransduction in the global synchronization of the uterus. The results also permit us to evidence the effect on IUP of this enhanced synchronization induced by the presence of SACs. This proposed simplified model will be further improved in order to permit a better understanding of the global uterine synchronization occurring during efficient labor contractions.
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Affiliation(s)
- Maxime Yochum
- Sorbonne University, Université de Technologie de Compiègne, CNRS UMR 7338, Biomechanics and Bioengineering, Centre de Recherche Royallieu, CS 60319-60203 Compiègne cedex, France.
| | - Jérémy Laforêt
- Sorbonne University, Université de Technologie de Compiègne, CNRS UMR 7338, Biomechanics and Bioengineering, Centre de Recherche Royallieu, CS 60319-60203 Compiègne cedex, France.
| | - Catherine Marque
- Sorbonne University, Université de Technologie de Compiègne, CNRS UMR 7338, Biomechanics and Bioengineering, Centre de Recherche Royallieu, CS 60319-60203 Compiègne cedex, France
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31
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Myers KM, Elad D. Biomechanics of the human uterus. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [PMID: 28498625 DOI: 10.1002/wsbm.1388] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/23/2017] [Accepted: 03/01/2017] [Indexed: 12/15/2022]
Abstract
The appropriate biomechanical function of the uterus is required for the execution of human reproduction. These functions range from aiding the transport of the embryo to the implantation site, to remodeling its tissue walls to host the placenta, to protecting the fetus during gestation, to contracting forcefully for a safe parturition and postpartum, to remodeling back to its nonpregnant condition to renew the cycle of menstruation. To serve these remarkably diverse functions, the uterus is optimally geared with evolving and contractile muscle and tissue layers that are cued by chemical, hormonal, electrical, and mechanical signals. The relationship between these highly active biological signaling mechanisms and uterine biomechanical function is not completely understood for normal reproductive processes and pathological conditions such as adenomyosis, endometriosis, infertility and preterm labor. Animal studies have illuminated the rich structural function of the uterus, particularly in pregnancy. In humans, medical imaging techniques in ultrasound and magnetic resonance have been combined with computational engineering techniques to characterize the uterus in vivo, and advanced experimental techniques have explored uterine function using ex vivo tissue samples. The collective evidence presented in this review gives an overall perspective on uterine biomechanics related to both its nonpregnant and pregnant function, highlighting open research topics in the field. Additionally, uterine disease and infertility are discussed in the context of tissue injury and repair processes and the role of computational modeling in uncovering etiologies of disease. WIREs Syst Biol Med 2017, 9:e1388. doi: 10.1002/wsbm.1388 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Kristin M Myers
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - David Elad
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel.,Department of Biomedical Engineering, Columbia University, New York, NY, USA
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32
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Gora S, Elad D, Jaffa AJ. Objective Analysis of Vaginal Ultrasound Video Clips for Exploring Uterine Peristalsis Post Vaginal and Cesarean Section Deliveries. Reprod Sci 2017; 25:899-908. [PMID: 28345486 DOI: 10.1177/1933719117697256] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The nonpregnant uterus is characterized by cyclic contractions that assist in sperm transport to the fallopian tube, embryo transport to implantation site, and expulsion of menstrual debris. The effect of post-Cesarean section (CS) scar on uterine peristalsis is unclear, while worldwide the prevalence of CS deliveries is increasing. In this study, we developed a new objective method for analysis of dynamic characteristics of the nonpregnant uterus from transvaginal ultrasound (TVUS) recordings when the uterine cavity is not clearly observed, as may be the case in post-CS uteri. The method of active contours was utilized to detect the contours of the endometrium-myometrium interface (EMI) from sagittal cross-section TVUS images of nonpregnant uteri. The contours were straightened along the uterus centerline and registered with respect to the fundal end in order to reduce the noise due to movements of the physician and the participant. A dynamic analysis was conducted on these time-dependent contours in order to explore the frequency and amplitude of the EMI motility. The analysis was conducted on TVUS video clips from 12 nonpregnant participants, 7 post-CS and 5 controls. The frequencies of the EMI motility was 0.010 to 0.064 Hz at days 8 to 17 in the control participants and 0.014 to 0.073 Hz at days 9 to 15 in post-CS participants. The maximal amplitude of motility was 0.67 to 2.00 mm and 0.48 to 2.58 mm for the control and post-CS participants, respectively. In this preliminary study, we have not observed significant difference between the EMI motility of healthy and post-CS uteri.
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Affiliation(s)
- Silvia Gora
- 1 Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - David Elad
- 1 Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Ariel J Jaffa
- 2 Ultrasound Unit in Obstetrics and Gynecology, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.,3 Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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