Baby Fetal Doppler Monitor: Listening to Baby’s Heartbeat

By Myrah M.

Pregnancy is a special yet challenging time in a mother’s life. While you may feel elated at the thought of a baby growing in you, you also will have concerns about the health of your growing child, especially in the first trimester when it is impossible to feel the baby’s movement. Hearing your baby’s heartbeat can be comforting for most mothers, especially those who have had a stillbirth, miscarriage, or difficulty conceiving.

Fortunately, even though you might not feel the baby’s motions that early in pregnancy, you could possibly hear the reassuring heartbeat of your baby as early as 6 weeks with a transvaginal ultrasound, or 8 weeks with a home fetal doppler. However, during the first trimester, the baby is still very tiny, making it very challenging to hear a heartbeat on a home fetal doppler. It is recommended to wait until after 12 weeks of pregnancy (or even up to 16 weeks) before using an at-home fetal doppler for more accurate readings.

What is a home fetal doppler?

An at-home fetal doppler is a small device that uses sound waves to detect a baby's heartbeat through a pregnant woman’s belly. Like an ultrasound machine, a home fetal doppler detects changes in movement which are translated into sound. This sound is transmitted through a built-in speaker or earphones and allows you to share the special moment with loved ones. Fetal dopplers typically run on batteries and have a probe for gliding over the belly. Most at-home fetal dopplers have a screen to display the fetal heart rate. Others have a color screen as well as a digital display.

How do you safely use an at-home fetal doppler?

You may be excited to get started using an at-home fetal doppler, but be sure to follow the manufacturer’s instructions carefully as well as a few of the following safety guidelines:

• Lie back in a comfortable position, preferably in a quiet place
• Apply sonogram gel to your exposed lower abdomen
• Turn on the doppler and raise the volume
• Spread the gel with the fetal doppler probe
• Keeping the probe on your belly, start at the pubic area located directly under the belly
• Slide probe up to the belly button area
• Then slide probe from one end of the belly to the other
• Slowly move it around until you hear the baby’s heartbeat
• If your baby is big enough, you can also find your baby’s location by feeling with your hands
• If the heartbeat is not found after a few minutes, turn off the device and try again later
• Use the device for only a limited amount of time, generally no longer than 10 minutes
• Wipe the gel off your stomach with a towel
• Clean the machine after each use
• Turn off the device and keep away from children

When can you start using an at-home fetal doppler?

The uterus does not emerge from within the pelvis until around the end of the first trimester; thus, using a doppler monitor earlier than 12 weeks can be challenging since you may have a difficult time detecting the baby’s heartbeat. During this early period, your best bet for listening to your baby’s heartbeat is during your ultrasounds at your doctor’s appointments. Although some at-home fetal dopplers can pick up the heartbeat as early as 8 weeks (and some as late as 28 weeks), it is still best to wait at least 12 weeks into the pregnancy prior to using a doppler at home.

Is it safe to use an at-home fetal doppler?

The home fetal doppler is based on the same principle as the ultrasound and has not been shown to cause any harm to the developing fetus. The doctor typically uses a fetal doppler to monitor your baby during your visits and may ask you to use one at home to check your baby’s heart rate, especially if you’re at risk for a complicated pregnancy from diseases like diabetes and high blood pressure. Although the at-home fetal doppler can be useful, it can also be subject to misuse. It carries a risk of misinterpretation of results or inaccuracy in results when not used according to the manufacturer’s recommendations. Remember that an at-home fetal doppler is not a substitute for your appointments/ultrasounds but rather should be used in conjunction with your routine appointments.

Are at-home fetal dopplers accurate?

Pocket fetal dopplers are designed to give you a general idea of your baby's development and help you monitor your baby's well-being between your routine ultrasound appointments. Studies show that fetal heart rate dopplers are safe and give comparable results to ultrasounds. However, remember that the ultrasound machine is a more powerful piece of equipment used by trained medical professionals, so you might sometimes get a different heart rate at home than at the doctor’s due to the differences in the device and technique of use.

Can at-home fetal dopplers cause a miscarriage?

Using a fetal doppler at home is safe and has not been shown to cause a miscarriage. If used appropriately, they can help reduce the chances of certain complications by detecting changes that might trigger a visit to your doctor. However, do not depend on an at-home doppler for any medical diagnosis as the doppler is not intended for that. Follow up with your doctor for all regularly scheduled appointments and for evaluation of any medical concerns you might have.

Can you use a fetal heartbeat doppler without a gel?

You should not use a fetal heartbeat doppler without a gel. The gel is a simple lubricant that eliminates air pockets between the womb and doppler, creates a tight seal between the body and the device, and allows sound to travel better. The gel also prevents the fetal heart rate doppler from heating up and serves as lubrication to help the probe slide easier along your abdomen. You can use an ultrasound gel or substitute with easily available lubricants such as aloe-vera, coconut oil, KY-jelly, or baby oil.

What is the normal fetal heart rate?

Even though babies have a fast heartbeat during the first trimester, they are so hard to detect as the baby is still very tiny. As the fetus grows, the heartbeat settles into 110-160 beats per minute with a fluctuation of 5 to 25 beats per minute (bpm). This means that your baby’s heartbeat can vary from 110 to 135 bpm (+25 bpm) or even from 135 to 160 bpm (+25 bpm) – all within the same timeframe. This explains some of the variance in heart rate you might experience when you use an at-home doppler monitor. And no doubt, this can be a cause for concern, especially if your doctor’s office reading is different from what you get at home. However, that slight variation in heart rate is normal and expected as your fetus grows. If you, however, experience any sudden decrease in heart rate or reduction in your baby's movement (especially at a later stage of pregnancy), be sure to address your concern with your healthcare provider.

How do you find your baby’s heartbeat during pregnancy?

You can listen to your baby’s heartbeat with an ultrasound at your doctor’s office. You can find your baby’s heartbeat with an at-home fetal monitor by placing a small amount of gel on the probe at the end of the monitor and placing the probe near your lower abdomen, under your belly button, close to your pubic bone. Be sure to follow the manufacturer’s instructions to ensure accurate readings.

Can you detect your baby's heartbeat earlier than 9 weeks?

Some fetal doppler heart monitors claim to detect a baby's heart rate as early as 8 weeks; however, it is challenging even for a doctor to detect a fetal heart rate that early in pregnancy since the baby is tiny. Typically, most fetal heartbeat dopplers will detect a baby's heartbeat after 12 weeks. If you desire to hear your child's heartbeat earlier than 12 weeks into your pregnancy, your best bet is to have an ultrasound done in the hospital by a trained medical professional.

Can you hear your baby's heartbeat without a doppler?

It is pretty challenging to hear your baby's heartbeat without a fetal heart rate doppler; however, you can listen to your baby's heartbeat by using other instruments such as a stethoscope, which amplifies small sounds like your baby's heartbeat. Unfortunately, a stethoscope does not detect heart rate as early as the ultrasound or pocket fetal doppler. If you do want to try using a stethoscope, you should be able to hear the baby’s heartbeat around 20 weeks into your pregnancy.

How do you distinguish your own heartbeat from the fetal heartbeat?

There are different factors you must consider when trying to verify that the heartbeat you’re hearing is indeed the baby’s and not yours.

• Rhythm and rate: Your baby's heart rate is faster than yours, so as a rule of thumb, hearing a rate of about 60-80 bpm is likely your own. A beat of >100 beats is very likely that of your baby.
• Use the fetal doppler at home when you have a full bladder; this helps push your uterus up from the pelvis and makes it easier to detect the baby’s heart rate rather than other sounds from your body.
• Go slow, especially if it is your first time listening to your child's heartbeat.
• Explore and familiarize yourself with the sound you should be listening for. Pay attention to the sound of your baby’s heartbeat during your ultrasound appointments so you recognize the sound.

How can you detect a fetal heartbeat in twins with a pocket fetal doppler?

Unless your doctor has already told you that you are pregnant with twins after an ultrasound, you shouldn't depend on an at-home fetal heartbeat doppler to confirm a pregnancy with twins. This is because you can hear the heartbeat of a single baby at different points, which can be mistaken as two separate heartbeats. However, if you do have a confirmed pregnancy with twins, then:

• Start from the lower part of your abdomen at your pubic region
• Apply gel as directed
• Move the probe slowly until you can hear the sound of your baby’s heartbeat
• Keep moving the probe until you can detect another distinct heartbeat
• Remember that the fetal pulse is faster than yours
• Twins often lie in different positions, making it sometimes challenging to detect both heartbeats, especially in the first trimester
• Practice makes perfect. As they grow bigger, you will get better at finding both heartbeats with your doppler

Can using your at-home fetal doppler heart monitor be a good substitute for hospital appointments?

The fetal heart rate monitor is not a good substitute for appointments with your doctor. Remember that your pregnancy care involves more than just listening to your baby’s heartbeat with a fetal doppler. The doctor performs other tests, labs, procedures, and evaluations to ensure that you and your baby are thriving. Skipping appointments can be detrimental as pregnancy complications could be missed without proper prenatal care.

Troubleshooting a doppler when it doesn’t detect a heartbeat

Detecting the fetal heart rate can be tricky, even when your baby is fine and developing appropriately. Not hearing a heartbeat with your at-home fetal monitor does not mean something is wrong. If you are worried about your baby, be sure to see doctor.

There are some influencing factors that might make it harder to detect a heartbeat with a doppler.
• Stage of your pregnancy: During early pregnancy, the uterus sits within the pelvis, making it nearly impossible for a home fetal heartbeat doppler to detect your baby’s heartbeat. This is normal. Around the end of the first trimester and into the second trimester, the uterus continues to grow out of the pelvis and rise into the abdomen. At this time, a sensitive doppler might be able to pick up your baby’s heartbeat.
• The position of the placenta: The location of the placenta can affect your ability to hear the fetal heartbeat. Depending on where the placenta is positioned, it can serve as a barrier between the fetal doppler and your baby, making it difficult to detect the fetal heartbeat.
• Position of the uterus: While most women’s uteruses are in the anteverted position, i.e. leaning forward and resting on the bladder, others (about 1 in 5) are in a retroverted position, i.e. leaning back towards the spine. For this latter group, it might be challenging to detect the fetal heart rate early in pregnancy. However, as pregnancy progresses, the uterus enlarges, and it usually returns to the normal position of leaning forward at around 16 weeks of pregnancy. This means that detecting a heartbeat in a pregnant woman with a retroverted uterus can be challenging until the uterus most times, self-corrects in the second trimester.
• Fetal death: In rare cases, absence of a fetal heartbeat could mean fetal death (miscarriage if less than 20 weeks’ pregnant and stillbirth after 20 weeks of pregnancy). If fetal death is suspected, your doctor will conduct some tests, including ultrasounds for confirmation of loss of pregnancy.

Listening to your baby’s heartbeat is an intimate experience. A fetal doppler reduces anxiety for most expectant mothers and facilitates bonding with your unborn child. The at-home doppler also allows a pregnant woman to share the miracle of pregnancy with loved ones in a non-invasive, painless, and safe way.