title: [Transvaginal detection of fetal heart rate by the ultrasonic Doppler method during early pregnancy].
mesh_terms: D005260:Female; D005318:Fetal Heart; D005865:Gestational Age; D006339:Heart Rate; D006801:Humans; D008722:Methods; D011247:Pregnancy; D014463:Ultrasonography; D014621:Vagina