Mithu Kuna 
Heartbeats are the sound of life so it’s understandable that any irregularities can make a mother worry.
Fetal arrhythmias—abnormalities in your baby’s heartbeat—are probably more common during pregnancy than you think.
Whether you discover the problem during an appointment or using your own fetal doppler, it’s easy to panic. But many cases only require simple lifestyle changes to get your baby’s heart rate back to normal.
In this post, we’re discussing what fetal heart arrhythmias are, the causes and the treatments you can expect.
What is a Fetal Heart Arrhythmia?
Once your baby is big enough, your doctor will be able to use a fetal doppler to detect her heartbeat. This will allow the doctor to hear her heart and get a measure on her fetal activity. Your baby’s fetal heart rate will let you know if she’s developing as expected.
Along with the beats per minute, your doctor also listens to the rhythm of the heartbeat. Is there a steady balance of beats and rests? Or are there random, unexpected extra or dropped beats?
A fetal heart arrhythmia is when an abnormal heart rate or rhythm is detected. The heart rate may be too fast, too slow or have dropped or extra beats. The condition is fairly common, happening in about 1-2% of pregnancies.
To envision what this sounds like, Dr. Robyn Horsager-Boehrer paints a good picture: “A normal beat sounds like “thump-THUMP-thump-THUMP” rhythm, but a fetus with a heart arrhythmia might sound like “thump … THUMP-THUMP … thump.”
Fetal arrhythmias are usually detected during a normal pregnancy check-up. There’s typically no symptoms of it beforehand.
Types of Fetal Arrhythmias
A healthy heartrate range for a fetus depends on how far along you are in your journey. A normal heartrate is between 110 and 160 bpm but can be higher during certain periods, such as the first trimester.
Here are the main types of fetal arrhythmias a baby may have:
- Bradyarrhythmia— Bradyarrhythmia fetal arrhythmiahappens when the fetal heartrate is slower than usual (below 100bpm).
- Tachyarrhythmia—Tachyarrhythmia arrhythmia happens when the baby’s heartbeat is too fast (above 180bpm).
- Combinationof irregular rhythm and abnormal heart rate
- Ectopic rhythm— When the baby’s heart produces early beats. This may sound like extra or dropped beats.
The abnormal heartbeat may be detected the first time you hear your baby’s heart, or it may happen later during pregnancy.
Can At Home Dopplers Detect Fetal Arrhythmia?
When you have a pregnancy check-up, your doctor uses a fetal doppler (AKA a fetal heartbeat monitor) to check your baby’s fetal heart rate. There’s also fetal doppler models that you can purchase for home use.
If you use a fetal doppler at home, you may get used to patterns in your baby’s heartbeat. When you don’t hear the same thing, you may think you detect an abnormality. However, it’s important to remember that only professionals can diagnose conditions.
If you think you detect a dropped or extra beat at home, there may be other reasons to explain the difference. It’s possible you’re detecting the wrong noise or your baby has shifted positions. So, try not to panic. If you’re worried, you can record the heartbeat and send it to your doctor or midwife for advice.
It’s also worth noting that the more you use your fetal doppler at home, the more likely you may be to detect issues.
Dr. Robyn Horsager-Boehrer says that fetal heart arrhythmias are probably more common than we think because we only catch the issue during appointments.
“Chances are, if we listened more frequently during a woman’s pregnancy, we’d detect arrhythmias in more than the 1 to 2% we expect today.”
So although you may worry something is wrong with your baby, most irregularities aren’t serious, and you may just notice it because you’re using a doppler more frequently. Still, you should get any issues checked out.
Although fetal dopplers can’t be used to diagnose issues unless you’re a professional, they may provide some use for fetal arrhythmia. For example, your midwife may suggest using the device from time to time to monitor the heartbeat and alert them of anything abnormal. It can also provide reassurance for those with high-risk pregnancies.
Fetal Heart Arrhythmia Cause
Since fetal heart arrhythmia doesn’t have any symptoms you can feel, most women find out their baby has it during a routine appointment. Alternatively, if you use a fetal doppler, you may hear an abnormality yourself and ask your doctor to investigate further.
Diagnosing the Cause
If your doctor detects an abnormal rhythm, they will likely refer you to a specialist, like a maternal-fetal medicine doctor (MFM) or pediatric cardiologist.
During that appointment, the doctor will evaluate your baby’s heart structure and whether its development is normal. That could involve several tests, including a fetal echocardiogram. This will help your doctor determine whether the issue is caused by the heart or other factors, such as lifestyle choices.
Heart Structure Problems
In severe cases, arrhythmia may be caused by congenital heart defects, like a congenital heart block or long QT syndrome.
Lifestyle Choices
In most cases, the heart structure is normal and your baby is developing as expected. Your doctor can review the substances you’re using to determine if something you’re doing is causing the abnormality. If so, simple changes can help return your baby’s heartbeat back to normal (more on this in the section below).
Fetal Heart Arrhythmia Treatment
How you treat your baby’s heart arrhythmia depends on the cause. After you’re referred to a specialist, they’ll run tests to determine whether your baby has a heart issue or if other factors may contribute to the abnormality.
Lifestyle Changes
In many cases, fetal heart arrhythmia isn’t caused by heart issues and lifestyle changes will help. Although you may not know it, certain things you’re doing may cause your baby’s heartbeat or pattern to quicken or slow down.
- Fetal Heart Arrhythmia and Caffeine— Caffeine can cause your baby’s heartrate to speed up more than what is normal. Although more research needs to be done, studies show that caffeine may heighten your risk of negative pregnancy outcomes, such as low birth weight. Most experts recommend keeping to one cup of coffee per day. If you’re drinking more than that amount, your doctor may recommend cutting down. If you’ve already cut down, you may consider cutting it out completely and seeing if it helps lower your baby’s heart rate. But even if you pay attention to your coffee intake, caffeine is hiding in other foods too. For example, dark chocolate or coffee-flavored desserts may contain enough caffeine to impact your baby. Migraine medications containing caffeine could be a cause too.
- Caffeinated Creams— Although you may not suspect it, some creams and lotions have enough caffeine to impact your baby and change her heartbeat. Specifically, stretch mark prevention lotions can contain higher amounts of caffeine. Since many women use these to stop marks during pregnancy, it can be a common culprit. Although stretchmark creams are typically safe to use, you may need to switch it out for another lotion to determine if it’s the cause.
- Nicotine— Smoking during pregnancy can cause a variety of issues, one of those being an irregular heart rate. Vaping can have the same effect. If you’re having trouble quitting, it’s important to talk to your doctor so they can offer suggestions. Try these 8 Tips to Stop Smoking.
Medical Intervention
In other cases, your doctor may recommend medication for your condition.
In severe cases, your baby’s irregularity may put her at risk for fetal heart failure, which can be a risk to her and you. This requires adult cardiologists and a variety of possible therapies.
In most cases, your baby’s heart rate will be monitored more closely throughout your pregnancy to ensure the treatment is working and the problem isn’t getting worse. You may also be monitored to prevent hydrops, which can happen in severe cases of fetal cardiac arrhythmia.
This may require more frequent check-ups. Alternatively, some doctors may recommend getting an at-home fetal doppler and alerting them if you suspect any irregularities.
Summary of Fetal Heart Arrhythmias
During your routine pregnancy appointments, your doctor will use a fetal doppler to check your baby’s heart rate and rhythm. Any differences can indicate a fetal hearth arrhythmia. Alternatively, you may be using a fetal heart monitor at home and notice the change yourself. Since you can’t diagnose issues, you can share a recording of the heartbeat with your doctor to confirm or deny your suspicions.
To determine the cause of a fetal arrhythmia, your doctor will likely send you to a specialist who will run several tests. It’s possible that the abnormality is caused by a heart condition. However, most commonly, the issue isn’t serious and can be solved with some lifestyle changes. Substances containing caffeine and nicotine can cause heart rate abnormalities. Your doctor may ask you to reflect on the substances you’re using or consuming to pinpoint the culprit.
P.S. Hear Your Fetus From Home. Get a Fetal Doppler Today!
