Fetal Doppler

Fetal Doppler, India:

A fetal Doppler is an electronic instrument used to measure the heartbeat of the fetus or the tiny baby growing within the womb of the mother. It is very essential to know the heart beat rate to ascertain if the baby is growing normally. It is hand held instrument and some of these also display the rate of heart beat per minute.

The function of the fetal Doppler is similar to that of the fetal stethoscope. Unlike the stethoscope the Doppler is a modern invention. The Doppler comes in several frequencies. Hence it is possible to determine the heart rate of the fetus from early pregnancy, starting from the sixth week onwards. It is safe to use as it does not use any ultra-high frequency rays and works only on impulses.

The advantages of using a fetal Doppler are as follows.

• Safe for the mother and the fetus in the womb  
• Can start using from early pregnancy.
• Hand held and easy to use

It is advisable to use the Doppler by qualified medical professionals. Close monitoring of it usage is required throughout the pregnancy.

Some good models for even home use are:

• Nidek Fetal Doppler 210
• Niscomed Pocket Fetal Doppler (ND 102)

Fetal Doppler works on the principle of the Doppler Effect. That is, a sound pitch increases as the source moves toward the listener and reduces as it moves away. It is similar to a car or train as it moves away, and the change in the sound is the Doppler Effect. A fetal Doppler sends short sound impulses into the body of the mother and pauses between the pulses for the returning sound. The Doppler then determines the range of these sounds and converts it into an audible sound. This sound helps determine the rate of heart beat of the fetus. The sound is a representation of the fetal heart.  

Fetal dopplers are of two types, regular and digital. The regular Doppler just gives the sound of the heart beat which has to be counted to get the result. The digital Doppler gives a display of the reading in a small liquid crystal display screen.