title: The significance of amplitude and duration of fetal heart rate acceleration in non-stress test analysis.
abstract: OBJECTIVE
  This study was conducted to assess the relative significance of the amplitude versus the duration of accelerations in non-stress test (NST) analysis.
  
  
  METHODS
  A total of 3055 normal fetal heart rate (FHR) tracings at 30-42 weeks' gestation were analyzed by automated FHR analyzing software. Accelerations were classified as one of four combinations of amplitude and duration: 15 bpm-15 seconds (Acc15-15), 15 bpm-10 seconds (Acc15-10), 10 bpm-15 seconds (Acc10-15) and 10 bpm-10 seconds (Acc10-10). We estimated the correlation among the FHR acceleration combinations using correlation analysis based on linear regression models.
  
  
  RESULTS
  Linear regression models demonstrated statistically significant linear associations between Acc15-15 and Acc15-10 (r(2) = 0.998, p < 0.0001) and between Acc10-10 and Acc10-15 (r(2) = 0.989, p < 0.0001). There was significant association based on amplitude and relatively low correlation based on duration (Pearson correlation coefficient = 0.99 between Acc10-10 and Acc10-15, and 0.99 between Acc15-15 and Acc15-10). In the relationships of the FHR-work values, amplitude was a more important component of FHR acceleration than duration [Acc10-10 (1.67 beat) < Acc10-15 (2.50 beats) = Acc15-10 (2.50 beats) < Acc15-15 (3.75 beats)].
  
  
  CONCLUSIONS
  Amplitude was a more significant component of FHR acceleration than duration in the computerized analysis of NST.
authors.affiliation: Department of Obstetrics and Gynecology, Hanyang University, Seoul, South Korea.
authors.forename: Jeong-Kyu
authors.initials: JK
authors.lastname: Hoh
authors.forename: Moon-Il
authors.initials: MI
authors.lastname: Park
authors.forename: Young-Sun
authors.initials: YS
authors.lastname: Park
authors.forename: Seung-Kwon
authors.initials: SK
authors.lastname: Koh
mesh_terms: D000054:Acceleration; D001330:Electronic Data Processing; D005260:Female; D005323:Fetal Monitoring / Q000379:methods*; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D011247:Pregnancy; D013997:Time Factors