At approximately what gestational age are fetal heart sounds audible by Doppler?

At approximately what gestational age are fetal heart sounds audible by Doppler?

• A. 12 weeks
• B. 20 weeks
• C. 24 weeks
• D. 16 weeks

Answer: (D)

Hearing fetal heart tones with Doppler depends on the fetus growing larger and the signal becoming clearer through the maternal abdomen. While Doppler can sometimes detect heart activity earlier, the finding is most reliably present around mid-pregnancy. By about 16 weeks, the fetal heart is sufficiently large and the acoustic window is usually favorable, so Doppler detection is consistently achievable in most pregnancies. Earlier times, like around 12 weeks, can be variable and depend on device sensitivity and maternal factors, whereas 20 or 24 weeks are later than necessary for this expectation. So, 16 weeks is the typical approximate point at which Doppler audibility becomes reliably achievable.

Hearing fetal heart tones with Doppler depends on the fetus growing larger and the signal becoming clearer through the maternal abdomen. While Doppler can sometimes detect heart activity earlier, the finding is most reliably present around mid-pregnancy. By about 16 weeks, the fetal heart is sufficiently large and the acoustic window is usually favorable, so Doppler detection is consistently achievable in most pregnancies. Earlier times, like around 12 weeks, can be variable and depend on device sensitivity and maternal factors, whereas 20 or 24 weeks are later than necessary for this expectation. So, 16 weeks is the typical approximate point at which Doppler audibility becomes reliably achievable.