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What is a Prenatal Heart Monitor?

Lindsey Rivas
Lindsey Rivas

A prenatal heart monitor is a device that detects high frequency sound waves produced by a baby’s heart while in the womb so that others can hear the heartbeat. The monitor typically includes a wand or probe that is placed on a pregnant woman's belly along with a hand-held box that plays the sound and may provide a digital readout. Being able to hear a baby’s heartbeat can provide comfort to a mother as well as indicate if there are problems with the baby. This type of monitor is typically used by doctors at prenatal visits, but there are some that can also be used at home. A prenatal heart monitor for use at home can either be purchased or rented.

When using a prenatal heart monitor, gel or lotion would be applied to a pregnant woman’s belly to help transmit the sound. The probe is then moved around the belly and pelvic area at different angles to find the baby’s heartbeat. Once the beat is detected, the sound will come through the monitor box as a fast, pulsing heartbeat. A baby’s heart will beat much faster than an adult’s, so one is able to distinguish between the baby’s heartbeat and that of the mother. Some monitors will have a digital readout that will display the number of beats per minute and a line graph of the heartbeat as peaks and valleys.

Doctor with a baby
Doctor with a baby

During prenatal doctor visits, a doctor will typically use a prenatal heart monitor to check the development of a baby’s heart and make sure the heartbeat is in the normal range. If the beat is faster or slower than what is considered normal, it can alert the doctor to medical problems or conditions such as distress in the baby. A prenatal heart monitor is also usually used at the hospital during labor and delivery to constantly monitor the status of the baby before birth. Most of the time it will be an external monitor that can be strapped to a pregnant woman’s belly, but in some cases an internal monitor will need to be attached to the baby directly.

A prenatal heart monitor might also be used at home. For a woman who has had previous miscarriages or is having a complicated pregnancy, being able to hear the baby’s heartbeat can provide a measure of comfort and sometimes prevent unnecessary trips to the emergency room. Some monitors can detect a baby’s heartbeat as early as eight weeks into the pregnancy, but most of the time it is after 10 to 12 weeks. In addition, many home-use monitors will have the ability to record the heartbeat for later playback.

In order to use a prenatal heart monitor at home, it would need to be either purchased or rented. Purchasing one can cost several hundred US dollars (USD), so in some cases it might be more economical to rent one for a low monthly fee. Also, a prescription-grade prenatal monitor often requires a doctor’s approval to obtain. In contrast to those, there are some types of monitors which are simply Doppler units that allow one to hear a baby’s heartbeat only. These are available at retail stores and are relatively inexpensive compared to prescription monitors.

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    • Doctor with a baby
      Doctor with a baby