title: Improvements in fetal heart rate analysis by the removal of maternal-fetal heart rate ambiguities.
abstract: BACKGROUND
  Misinterpretation of the maternal heart rate (MHR) as fetal may lead to significant errors in fetal heart rate (FHR) interpretation. In this study we hypothesized that the removal of these MHR-FHR ambiguities would improve FHR analysis during the final hour of labor.
  
  
  METHODS
  Sixty-one MHR and FHR recordings were simultaneously acquired in the final hour of labor. Removal of MHR-FHR ambiguities was performed by subtracting MHR signals from their FHR counterparts when the absolute difference between the two was less or equal to 5 beats per minute. Major MHR-FHR ambiguities were defined when they exceeded 1% of the tracing. Maternal, fetal and neonatal characteristics were evaluated in cases where major MHR-FHR ambiguities occurred and computer analysis of FHR recordings was compared, before and after removal of the ambiguities.
  
  
  RESULTS
  Seventy-two percent of tracings (44/61) exhibited episodes of major MHR-FHR ambiguities, which were not significantly associated with any maternal, fetal or neonatal characteristics, but were associated with MHR accelerations, FHR signal loss and decelerations. Removal of MHR-FHR ambiguities resulted in a significant decrease in FHR decelerations, and improvement in FHR tracing classification.
  
  
  CONCLUSIONS
  FHR interpretation during the final hour of labor can be significantly improved by the removal of MHR-FHR ambiguities.
authors.affiliation: Hospital Nélio Mendonça, Funchal, Portugal. paula.pinto14@gmail.com.|Departamento de Obstetrícia e Ginecologia, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. paula.pinto14@gmail.com.
authors.forename: Paula
authors.initials: P
authors.lastname: Pinto
authors.affiliation: Center for Health Technology and Services Research (CINTESIS), Porto, Portugal. csantos@med.up.pt.
authors.forename: Cristina
authors.initials: C
authors.lastname: Costa-Santos
authors.affiliation: Center for Health Technology and Services Research (CINTESIS), Porto, Portugal. hernanigoncalves@med.up.pt.
authors.forename: Hernâni
authors.initials: H
authors.lastname: Gonçalves
authors.affiliation: Departamento de Obstetrícia e Ginecologia, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. sisporto@med.up.pt.|Centro Hospitalar São João, Porto, Portugal. sisporto@med.up.pt.|INEB - Institute of Biomedical Engineering; I3S - Institute for Research and Innovation in Health, University of Porto, Porto, Portugal. sisporto@med.up.pt.
authors.forename: Diogo
authors.initials: D
authors.lastname: Ayres-De-Campos
authors.affiliation: Departamento de Obstetrícia e Ginecologia, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. jbernardes59@gmail.com.|Center for Health Technology and Services Research (CINTESIS), Porto, Portugal. jbernardes59@gmail.com.|Centro Hospitalar São João, Porto, Portugal. jbernardes59@gmail.com.|Unidade Local de Saúde de Matosinhos, Hospital Pedro Hispano, Matosinhos, Portugal. jbernardes59@gmail.com.
authors.forename: João
authors.initials: J
authors.lastname: Bernardes
mesh_terms: D000328:Adult; D015148:Cardiotocography / Q000592:standards*; D005260:Female; D006340:Heart Rate, Fetal; D006801:Humans; D007231:Infant, Newborn; D007743:Labor, Obstetric / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D055815:Young Adult