Fetal Dopplers are very common in the OB setting (office, labor & delivery, etc.). Practitioners typically begin to use them around the 12th week of gestation to listen to fetal heart tones, and continue to use them throughout the pregnancy.
Vascular Dopplers typically are used by cardiologists, vascular specialists and primary care physicians, as well as other doctors concerned with blood flow in the arteries, veins and, especially, the extremities.
Description of the typical probes
2MHz – This is a later term obstetrical probe and will attain deeper penetration. This is often the choice for anything after 21 weeks gestation.
3MHz – This is the early term obstetrical probe. It is more peripheral than the 2MHz and often used in the office assessments.
4MHz – This is a very deep penetration vascular probe that is best suited to areas requiring assessment of deep arterial sounds.
5MHz – This probe is commonly paired with the 8MHz probe as a good selection for total vascular assessments.
8MHz – This is the most popular probe for peripheral detection such and ABI (Ankle, Brachial Index) assessments. Those looking for pedal pulses, brachial pulses and digital pulses will prefer the 8MHz.