Four leads in fetal electrocardiography.
D004562:Electrocardiography; D004566:Electrodes; D005188:False Negative Reactions; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis; D005318:Fetal Heart / Q000502:physiology*; D005865:Gestational Age; D006339:Heart Rate; D006801:Humans; D008722:Methods; D011247:Pregnancy