This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis in Obstetrics, Subject name: Gynaecology & Obstetrics
The earliest sign of foetal life is best detected by: 
Select and explain. 
A. Doppler, B. Real-time ultrasound, C. Fetoscopy, D. Clinical examination
B: Real-time ultrasound
Answer: B: Real-time ultrasound 
Explanation: Ans. B. Real-time ultrasoundRecording the presence or absence of fetal life can generally be accomplished by real-time ultrasound by 6th week (TAS) or 5th week (TVS) counting from first day of last menstrual period.The routine use of doppler in pregnancy remains controversial, with concern about the increased power intensities when compared with imaging levels and with the widespread use of TVS.