title: Early detection of heart action in the fetus and determination of placenta position with the Doppler ultrasonic method.
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis; D000669:Amplifiers, Electronic; D003937:Diagnosis, Differential; D005260:Female; D005313:Fetal Death / Q000175:diagnosis; D005318:Fetal Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D010920:Placenta / Q000033:anatomy & histology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D014159:Transducers; D014465:Ultrasonics; D014463:Ultrasonography; D014594:Uterine Neoplasms / Q000175:diagnosis