title: Noninvasive in utero assessment of PR and QRS intervals from the fetal magnetocardiogram.
abstract: Fetal cardiac waveform intervals were assessed from fetal magnetocardiogram (FMCG) recordings taken from 59 pregnant women at 17-41 weeks gestation. Beyond 27 weeks' gestation PR and QRS intervals, measured from averaged waveforms, could be obtained from all subjects; however, prior to 21 weeks' gestation the success rate was 50% or less due to low signal-to-noise ratio. QT interval could not be assessed accurately in most subjects. Weak, but statistically significant, correlations with gestational age were found for PR interval (n = 145, R2 = 0.033, P = 0.028) and QRS interval (n = 145, R2 = 0.140, P < 0.0005). Abnormal waveform morphology was documented in several patients with cardiac malformations.
mesh_terms: D000328:Adult; D004562:Electrocardiography; D005260:Female; D005323:Fetal Monitoring / Q000379:methods*; D005865:Gestational Age; D006334:Heart Function Tests / Q000379:methods*; D006340:Heart Rate, Fetal; D006801:Humans; D008280:Magnetics; D011247:Pregnancy; D012680:Sensitivity and Specificity