title: Is there evidence of fetal-maternal heart rate synchronization?
abstract: BACKGROUND
  The prenatal condition offers a unique possibility of examining physiological interaction between individuals. Goal of this work was to look for evidence of coordination between fetal and maternal cardiac systems.
  
  
  METHODS
  177 magnetocardiograms were recorded in 62 pregnancies (16th-42nd week of gestation). Fetal and maternal RR interval time series were constructed and the phases, i.e. the timing of the R peaks of one time series in relation to each RR interval of the other were determined. The distributions of these phases were examined and synchrograms were constructed for real and surrogate pairs of fetal and maternal data sets. Synchronization epochs were determined for defined n:m coupling ratios.
  
  
  RESULTS
  Differences between real and surrogate data could not be found with respect to number of synchronization epochs found (712 vs. 741), gestational age, subject, recording or n:m combination. There was however a preference for the occurrence of synchronization epochs in specific phases in real data not apparent in the surrogate for some n:m combinations.
  
  
  CONCLUSIONS
  The results suggest that occasional coupling between fetal and maternal cardiac systems does occur.
authors.affiliation: Department of Biomagnetism, Research and Development Center for Microtherapy (EFMT), Bochum, D-44799 Germany. petervl@microtherapy.de
authors.forename: Peter
authors.initials: P
authors.lastname: Van Leeuwen
authors.forename: Daniel
authors.initials: D
authors.lastname: Geue
authors.forename: Silke
authors.initials: S
authors.lastname: Lange
authors.forename: Dirk
authors.initials: D
authors.lastname: Cysarz
authors.forename: Henrik
authors.initials: H
authors.lastname: Bettermann
authors.forename: Dietrich H W
authors.initials: DH
authors.lastname: Grönemeyer
mesh_terms: D000328:Adult; D004562:Electrocardiography / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D005318:Fetal Heart / Q000502:physiology*; D005323:Fetal Monitoring / Q000379:methods; D005865:Gestational Age; D006339:Heart Rate / Q000502:physiology*; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D011247:Pregnancy