How Fetal Dopplers Work, Are They Safe?

Fetal Dopplers or baby heartbeat monitors are popular devices among pregnant women and soon to be dads because it helps them bond with their unborn child. While this device proves efficient in doing the job, some are concerned with its safety.

Are fetal Dopplers safe? This question is the leading concern among expectant moms and dads. Since this device can be bought over the counter or online, soon to be parents are alarmed because their priority is their child’s safety and they think that hearing their little one’s heartbeat is a form of reassurance but others said otherwise. Could there be any drawbacks? Some sources claim that this device is not safe and might harm the unborn child. Which is true?

How Fetal Dopplers Work?

A handheld baby heartbeat monitor or fetal Doppler uses a probe to detect the high frequency sound waves produced by the baby’s heart using ultrasound technology. This device only uses low emission ultrasound technology. To magnify the sound waves and enable the probe to pick it up, conductors like gel or oil are recommended.

The Doppler probe sends out the high-frequency sound waves that pass through your skin and tissue and into your baby. When these waves encounter movement like your baby’s heartbeat, it bounces back to the device and the device translates the movement into sound. The sound is amplified through the monitor. The monitors are regulated by the FDA and are approved for home use.

The drawback of this process is that it translates all the movements inside you into sound, including your baby’s kicks and hiccups, the air moving in your intestines or the blood flowing in your arteries. It takes a lot of patience and practice to successfully distinguish a baby’s heartbeat from the other sounds inside you.

Are Fetal Dopplers Safe?


According to Dr. Abhijoy Chakladar, the monitors itself are harmless, but using this device to reassure one’s pregnancy is not right and could be dangerous. Most moms and dads buy a fetal Doppler for this purpose, but Dr. Chakladar does not advise soon to be parents to get this device for the said reason.

The physician shared the tragic story of a pregnant woman who relied on a baby heartbeat monitor to reassure her baby’s condition. The expectant mom was nearly full-term with her first baby. She was already in her 38th week of pregnancy. On a Friday, she felt that her baby was not moving, so she used her fetal heartbeat monitor. When she heard the baby’s heartbeat, she felt that the baby was fine. When she visited her doctor on Monday, she didn’t like what she found out, the ultrasound scan showed that her baby had died.

The physician stressed that there was no way to know if the baby’s death could have been prevented had the mom contacted her doctor right away. However, fetal Dopplers gave false reassurance that delayed the woman from seeking medical attention. According to Dr. Chakladar, it takes experience to determine the baby’s correct heartbeat. So, if a mother feels that something is wrong, she should immediately visit her doctor instead of turning to baby heartbeat monitors.

“On their own, these monitors are harmless; it is their improper use by parents to reassure themselves, which can be dangerous,” said Dr. Chakladar. “These monitors can be great fun, and I would personally buy one. However, they are dangerous if they are used by untrained people as an alternative to seeking medical advice.”

Additional Baby Health Care Tips While Using Fetal Doppler

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There is no evidence suggesting that fetal Dopplers are harmful to your unborn child. In most cases, the risks arise due to, improper use and wrong purpose of getting the device. As mentioned, do not buy a baby heartbeat monitor to reassure yourself of a safe pregnancy. Here are some things that you should consider when using baby heartbeat monitors.

  1. If you notice any changes in your baby’s movements contact your midwife or doctors right away.
  2. Never use the fetal Doppler monitor or reassure your child’s condition
  3. Work closely with professionals such as midwives, doctors or obstetricians to help you determine your baby’s heartbeat accurately.
  4. Do not overuse the fetal Doppler – In general, using a fetal Doppler should not last over 10 minutes. If you’ve been trying to locate your baby’ heartbeat, but you can’t find it and it is already 10 minutes, you should take a break. It is recommended that you use a baby heartbeat monitor in short intervals, infrequently and after the first trimester.
  5. How to determine your baby’s heartbeat – As mentioned, every movement in your body is translated into sound, making it even more difficult for you to determine your baby’s heartbeat. The easiest way to spot on your baby’s heartbeat is to check the fetal heart rate value that is usually displayed on the monitor in beats per minute (BPM). A baby’s heart rate is higher than adults, it usually ranges between 120 to 180 beats per minute. Meanwhile, your heart rate is only between 60 to 100 beats per minute.

What To Consider When Buying A Fetal Doppler

If you haven’t bought a fetal Doppler yet, but you are determined to get one,no problem. Here’s a list of the things that you need to consider when buying a fetal Doppler:

  • Check if the product conforms to the safety standard.
  • Check if the device comes with a warranty.
  • Compare prices and the different offers. Some baby heartbeat monitors include batteries, gel, cases and other helpful accessories, while others don’t.
  • Check for instructions on how to interpret the noises that you will hear.
  • Only use gel that is formulated for ultrasound use. Other gels or oils may trigger excess static and damage the Doppler probe in the process.

Additional Warning On Fetal Dopplers

imageWhile everyone agrees that baby heartbeat monitors are safe, parents should never forget that these devices are great for bonding with your unborn child but is never good enough to reassure your pregnancy.

“Although there is a lack of evidence of any harm due to ultrasound imaging and heartbeat monitors, prudent use of these devices by trained health care providers is important,” said Shahram Vaezy, Ph.D., an FDA biomedical engineer.

They physician explained that ultrasound exposure can heat tissues slightly and produce very small bubbles or cavitation is some tissues. The long-term effect of tissue heating and cavitation are not known. Thus, controlled use is recommended.

“When the product is purchased over the counter and used without consultation with a health care professional taking care of the pregnant woman, there is no oversight of how the device is used. Also, there is little or no medical benefit expected from the exposure,” Vaez added. “Furthermore, the number of sessions or the length of a session in scanning a fetus is uncontrolled, and that increases the potential for harm to the fetus and eventually the mother.”


Fetal Dopplers itself are safe, the only risk is the way consumers use it. Expectant moms should control their frequency of usage. Moreover, soon-to-be parents should never rely on this device to reassure the condition of their unborn child. Always seek your doctor’s advice, in case you feel that something is off with your pregnancy. Do not use a baby heartbeat monitor as an alternative medical advice.