Biomag 96 pp 581-584 | Cite as

Determination of Changes in Fetal Cardiac Time Intervals and T/QRS Ratio During Pregnancy Using Magnetocardiography

  • P. Van Leeuwen
  • S. Lange
  • M. Schüßler
  • L. Lajoie-Junge
Conference paper


Several studies have indicated that fetal cardiac time intervals (CTI) derived from the electric or magnetic cardiac signal increase in the course of pregnancy [1–3]. Such changes can be related to the size, development and maturity of the fetal heart and may thus serve as a measure reflecting not only normal cardiac function, but also the intrauterine growth state of the fetus as a whole. Another parameter which can be determined from the fetal cardiac signal is the amplitude of the signal at depolarisation and repolarisation times. In particular, the ratio of the T wave amplitude to the QRS complex amplitude (T/QRS) has been shown to increase in response to hypoxia during labor [4]. Little is known about changes in such amplitudes in the course of pregnancy. Among other things, this is due to the difficulty in obtaining viable electrocardiographic (ECG) signals consistently at different gestational ages (GA). ECG examination of the fetal cardiac signal is limited by noise, maternal artifacts and the insulating effects of the vernix caseosa. In this respect, fetal magnetocardiography (FMCG) has been shown to be a simple, noninvasive, and effective method in fetal monitoring, registering high quality fetal cardiac activity anytime during the pregnancy from the second trimester onwaid. The acquisition of the fetal cardiac magnetic signal enables the analysis of signal morphology for the complete beat with great accuracy [2]. The purpose of this study was to register fetal cardiac activity at regulär intervals in the course of healthy pregnancies with magnetocardiography in order to determine fetal CTI and signal amplitudes accurately and to investigate the changes of these parameters over time.


Fetal Heart Cardiac Time Interval Repolarisation Time Fetal Cardiac Activity Fetal Electrocardiogram 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Pardi, G., Ferrazi, E., Cetin, I. The clinical relevance of the abdominal fetal electrocardiogram, J Perinat Med, 1986, 14: 371–377.Google Scholar
  2. [2]
    Quinn, A., Weir, A., Shahani, U., Bain, R., Maas, P., Donaldson, G. Antenatal fetal magnetocardiography: a new method for fetal surveillance? Br J Obstet Gynaecol, 1994, 101: 866–870.CrossRefGoogle Scholar
  3. [3]
    Brambati, B., Pardi, G. The intraventricular conduction time of fetal heart in uncomplicated pregnancies, Br J Obstet Gynaecol, 1980, 87: 941–948.CrossRefGoogle Scholar
  4. [4]
    Deans, A.C., Steer, PJ. The use of the fetal electrocardiogram in labour, Br J Obstet Gynaecol, 1994, 101: 9–17.CrossRefGoogle Scholar
  5. [5]
    Schulz, D.L., Giordano, D.A. Hearts of infants and children, Arch Pathol, 1962, 74: 464–471.Google Scholar
  6. [6]
    Zhuravlev, Y.E., Rossi, D., Emery, SJ. Clinical assessment of fetal magnetocardiography, In: Baumgartner, C., Deecke, L., Stroink, G., Williamson, S.J. Biomagnetism: Fundamental Research and Clinical Applications, Amsterdam, Elsevier/IOS Press, 1995: 700–703.Google Scholar
  7. [7]
    Murray, H.G. The fetal electrocardiogram: current clinical developments in Nottingham, J Perinat Med, 1986, 14: 399–403.CrossRefGoogle Scholar
  8. [8]
    Wang, M., Wakai, R.T., Henry, J., Forbes, E., Martin, C.B. Mapping of the fetal magnetocardiogram, In: Baumgartner, C., Deecke, L., Stroink, G., Williamson, S.J. Biomagnetism: Fundamental Research and Clinical Applications, Amsterdam, Elsevier/IOS Press, 1995: 696–699.Google Scholar

Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • P. Van Leeuwen
    • 1
  • S. Lange
    • 1
  • M. Schüßler
    • 2
  • L. Lajoie-Junge
    • 1
  1. 1.Department of BiomagnetismResearch and Development Center for Microtherapy (EFMT)BochumGermany
  2. 2.Department of ObstetricsMarienhospitalWittenGermany

Personalised recommendations