JoVE Logo
Faculty Resource Center

Sign In





Representative Results






Electromyometrial Imaging of Uterine Contractions in Pregnant Women

Published: May 26th, 2023



1Department of Physics, Washington University, 2Center for Reproductive Health Sciences, Washington University School of Medicine, 3Department of Obstetrics and Gynecology, Washington University School of Medicine, 4Department of Biomedical Engineering, Washington University, 5Mallinckrodt Institute of Radiology, Washington University School of Medicine, 6Department of Pediatrics, Washington University School of Medicine, 7Department of Cardiology, Washington University School of Medicine, 8Department of Women's Health, University of Texas at Austin, Dell Medical School
* These authors contributed equally

We present a protocol for conducting electromyometrial imaging (EMMI), including the following procedures: multiple electromyography electrode sensor recordings from the body surface, magnetic resonance imaging, and uterine electrical signal reconstruction.

During normal pregnancy, the uterine smooth muscle, the myometrium, begins to have weak, uncoordinated contractions at late gestation to help the cervix remodel. In labor, the myometrium has strong, coordinated contractions to deliver the fetus. Various methods have been developed to monitor uterine contraction patterns to predict labor onset. However, the current techniques have limited spatial coverage and specificity. We developed electromyometrial imaging (EMMI) to noninvasively map uterine electrical activity onto the three-dimensional uterine surface during contractions. The first step in EMMI is to use T1-weighted magnetic resonance imaging to acquire the subject-specific body-uterus geometry. Next, up to 192 pin-type electrodes placed on the body surface are used to collect electrical recordings from the myometrium. Finally, the EMMI data processing pipeline is performed to combine the body-uterus geometry with body surface electrical data to reconstruct and image uterine electrical activities on the uterine surface. EMMI can safely and noninvasively image, identify, and measure early activation regions and propagation patterns across the entire uterus in three dimensions.

Clinically, uterine contractions are measured either by using an intrauterine pressure catheter or by performing tocodynamometry1. In the research setting, uterine contractions can be measured by electromyography (EMG), in which electrodes are placed on the abdominal surface to measure the bioelectrical signals generated by the myometrium2,3,4,5,6,7. One can use the magnitude, frequency, and propagation features of electrical bursts

Log in or to access full content. Learn more about your institution’s access to JoVE content here

All methods described here have been approved by the Washington University Institutional Review Board.

1. MRI-safe marker patches, electrode patches, and rulers (Figure 1)

  1. Print the MRI and electrode patch templates (Figure 1A) on paper.
  2. Cut clear vinyl and silicone rubber sheets (Table of Materials) into 22 (vinyl) and 44 (rubber) rectangular (120 mm x 60 mm), a.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Representative MRI-safe patches and electrode patches are shown in Figure 1B,C, created from the template shown in Figure 1A. The bioelectricity mapping hardware is shown in Figure 1C, with the connections of each component marked in detail. Figure 2 shows the entire EMMI procedure, including an MRI scan of the subject wearing MRI patches (Figure 2A), 3D op.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Electromyography has indicated that the frequency and amplitude of uterine electrical signals alter during the gestational period2,16,25. Several studies have explored the uterine propagation patterns of uterine contractions in patients in active labor10,17,26,27,28. .......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

We thank Deborah Frank for editing this manuscript and Jessica Chubiz for organizing the project. Funding: This work was supported by the March of Dimes Center Grant (22-FY14-486), by grants from NIH/National Institute of Child Health and Human Development (R01HD094381 to PIs Wang/Cahill; R01HD104822 to PIs Wang/Schwartz/Cahill), by grants from Burroughs Wellcome Fund Preterm Birth Initiative (NGP10119 to PI Wang), and by grants from the Bill and Melinda Gates Foundation (INV-005417, INV-035476, and INV-037302 to PI Wang).


Log in or to access full content. Learn more about your institution’s access to JoVE content here

Name Company Catalog Number Comments
16 G Vinyl 54" Clear Jo-Ann Stores 1532449
3 T Siemens Prisma Siemens N/A MRI scanner
3M double coated medical tape – transparent MBK tape solutions 1522 Width - 0.5"
Active electrode holders with X -ring Biosemi N/A 17 mm
Amira Thermo Fisher Scientific N/A  Data analysis software
Bella storage solution 28 Quart clear underbed storage tote Mernards  6455002
Extreme-temperature silicone rubber translucent McMaster-Carr 86465K71 Thickness 1.32”
Gorilla super glue gel Amazon N/A
LifeTime carbide punch and die set, 9 Pc. Harbor Freight 95547
Optical 3D scan Artec 3D Artec Eva Lite
PDI super sani cloth germicidal wipes McKesson medical supply company Q55172 Santi-cloth
Pin-type active electrodes Biosemi Pin-type
REDUX electrolyte gel Amazon 67-05
Soft cloth measuring tape Amazon N/A any brand can be used
Sterilite layer handle box Walmart 14228604 Closed box
TD-22 Electrode collar 8 mm Discount disposables N/A
Vida scanner Siemens N/A MRI scanner
Vitamin E dl-Alpha 400 IU - 100 liquid softgels Nature made SU59FC52EE73DC3

  1. Hadar, E., Biron-Shental, T., Gavish, O., Raban, O., Yogev, Y. A comparison between electrical uterine monitor, tocodynamometer and intra uterine pressure catheter for uterine activity in labor. The Journal of Maternal-Fetal & Neonatal Medicine. 28 (12), 1367-1374 (2015).
  2. Schlembach, D., Maner, W. L., Garfield, R. E., Maul, H. Monitoring the progress of pregnancy and labor using electromyography. European Journal of Obstetrics, Gynecology, and Reproductive Biology. 144, S33-S39 (2009).
  3. Jacod, B. C., Graatsma, E. M., Van Hagen, E., Visser, G. H. A. A validation of electrohysterography for uterine activity monitoring during labour. The Journal of Maternal-Fetal & Neonatal Medicine. 23 (1), 17-22 (2009).
  4. Garfield, R. E., et al. Uterine Electromyography and light-induced fluorescence in the management of term and preterm labor. Journal of the Society for Gynecologic Investigation. 9 (5), 265-275 (2016).
  5. Devedeux, D., Marque, C., Mansour, S., Germain, G., Duchêne, J. Uterine electromyography: A critical review. American Journal of Obstetrics and Gynecology. 169 (6), 1636-1653 (1993).
  6. Jain, S., Saad, A. F., Basraon, S. S. Comparing uterine electromyography & tocodynamometer to intrauterine pressure catheter for monitoring labor. Journal of Woman's Reproductive Health. 1 (3), 22-30 (2016).
  7. Lucovnik, M., et al. Use of uterine electromyography to diagnose term and preterm labor. Acta Obstetricia et Gynecologica Scandinavica. 90 (2), 150-157 (2011).
  8. Garcia-Casado, J., et al. Electrohysterography in the diagnosis of preterm birth: a review. Physiological Measurement. 39 (2), 02 (2018).
  9. Maner, W. L., Garfield, R. E. Identification of human term and preterm labor using artificial neural networks on uterine electromyography data. Annals of Biomedical Engineering. 35 (3), 465-473 (2007).
  10. Rabotti, C., Mischi, M. Propagation of electrical activity in uterine muscle during pregnancy: a review. Acta Physiologica. 213 (2), 406-416 (2015).
  11. Cohen, W. R. Clinical assessment of uterine contractions. International Journal of Gynaecology and Obstetrics. 139 (2), 137-142 (2017).
  12. Maner, W. L., Garfield, R. E., Maul, H., Olson, G., Saade, G. Predicting term and preterm delivery with transabdominal uterine electromyography. Obstetrics & Gynecology. 101 (6), 1254-1260 (2003).
  13. Leman, H., Marque, C., Gondry, J. Use of the electrohysterogram signal for characterization of contractions during pregnancy. IEEE Transactions on Biomedical Engineering. 46 (10), 1222-1229 (1999).
  14. Vasak, B., et al. Uterine electromyography for identification of first-stage labor arrest in term nulliparous women with spontaneous onset of labor. American Journal of Obstetrics and Gynecology. 209 (3), e1-e8 (2013).
  15. Euliano, T. Y., et al. Monitoring uterine activity during labor: a comparison of 3 methods. American Journal of Obstetrics and Gynecology. 208 (1), e1-e6 (2013).
  16. Garfield, R. E., Maner, W. L. Physiology and electrical activity of uterine contractions. Seminars in Cell & Developmental Biology. 18 (3), 289-295 (2007).
  17. Rabotti, C., Bijloo, R., Oei, G., Mischi, M. Vectorial analysis of the electrohysterogram for prediction of preterm delivery: a preliminary study. 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE. , 3880-3883 (2011).
  18. Wu, W., et al. Noninvasive high-resolution electromyometrial imaging of uterine contractions in a translational sheep model. Science Translational Medicine. 11 (483), (2019).
  19. Wang, H., et al. Accuracy of electromyometrial imaging of uterine contractions in clinical environment. Computers in Biology and Medicine. 116, 103543 (2020).
  20. Cahill, A. G., et al. Analysis of electrophysiological activation of the uterus during human labor contractions. JAMA Network Open. 5 (6), 2214707 (2022).
  21. Wang, H., et al. Noninvasive electromyometrial imaging of human uterine maturation during term labor. Nature Communications. 14 (1), 1198 (2023).
  22. Kok, R. D., de Vries, M. M., Heerschap, A., vanden Berg, P. P. Absence of harmful effects of magnetic resonance exposure at 1.5 T in utero during the third trimester of pregnancy: A follow-up study. Magnetic Resonance Imaging. 22 (6), 851-854 (2004).
  23. Choi, J. S., et al. A case series of 15 women inadvertently exposed to magnetic resonance imaging in the first trimester of pregnancy. Journal of Obstetrics and Gynaecology. 35 (8), 871-872 (2015).
  24. Ray, J. G., Vermeulen, M. J., Bharatha, A., Montanera, W. J., Park, A. L. Association between MRI exposure during pregnancy and fetal and childhood outcomes. JAMA. 316 (9), 952-961 (2016).
  25. Benedetti, M. G., Agostini, V., Knaflitz, M., Bonato, P. Applications of EMG in clinical and sports medicine. Intech Open. , 117-130 (2012).
  26. Lange, L., et al. Velocity and directionality of the electrohysterographic signal propagation. PloS One. 9 (1), e86775 (2014).
  27. Planes, J. G., Morucci, J. P., Grandjean, H., Favretto, R. External recording and processing of fast electrical activity of the uterus in human parturition. Medical & Biological Engineering & Computing. 22 (6), 585-591 (1984).
  28. Mikkelsen, E., Johansen, P., Fuglsang-Frederiksen, A., Uldbjerg, N. Electrohysterography of labor contractions: propagation velocity and direction. Acta Obstetricia et Gynecologica Scandinavica. 92 (9), 1070-1078 (2013).
  29. Young, R. C. The uterine pacemaker of labor. Best Practice & Research. Clinical Obstetrics & Gynaecology. 52, 68-87 (2018).
  30. Goldenberg, R. L. The management of preterm labor. Obstetrics and Gynecology. 100 (5), 1020-1037 (2002).
  31. Rubens, C. E., et al. Prevention of preterm birth: harnessing science to address the global epidemic. Science Translational Medicine. 6 (262), 5 (2014).
  32. Shi, H., et al. Screen-printed soft capacitive sensors for spatial mapping of both positive and negative pressures. Advanced Functional Materials. 29 (23), 1809116 (2019).
  33. Lo, L. W., et al. An inkjet-printed PEDOT:PSS-based stretchable conductor for wearable health monitoring device applications. ACS Applied Materials and Interfaces. 13 (18), 21693-21702 (2021).
  34. Lo, L. W., et al. Stretchable sponge electrodes for long-term and motion-artifact-tolerant recording of high-quality electrophysiologic signals. ACS Nano. 16 (8), 11792-11801 (2022).

This article has been published

Video Coming Soon

JoVE Logo


Terms of Use





Copyright © 2024 MyJoVE Corporation. All rights reserved