You’re pregnant and you know it can be an exciting, beautiful experience. But you’re also a little nervous. You want some reassurance that everything is A-OK. Wouldn’t it be great if I could check on my little one right now? you find yourself thinking.

Or maybe you’re not so nervous as you are wanting to bond with your baby a little more — looking for a way to connect.

First, rest assured that you’re not alone in your concerns. Many people are anxious for peace of mind or eager to bond with baby — which is why at-home fetal dopplers are so popular.

A fetal doppler — whether at the doctor’s office or purchased for home use — is a hand-held ultrasound device that uses soundwaves to listen to a fetal heartbeat. When you go to your doctor for a check-up, they’ll use one of these devices — hopefully, not without warming the ultrasound gel first! — to detect your baby’s heartbeat from around 8 to 10 weeks.

If your doctor can’t hear a heartbeat in the first trimester, it’s not necessarily a cause for concern. Some dopplers (yes, even those you encounter at your OB’s office!) only detect it after about 12 weeks.

For many, hearing the heartbeat at the doctor’s office is a magical, joyful, and reassuring experience — and the time between appointments is just so darn long to wait to hear that sweet sound again! The idea of listening to the heartbeat in between doctor’s appointments is appealing. It may also ease anxiety and help you feel more connected to your baby.

So what’s the harm? Well, possibly very little.

But not so fast. It’s important to know about the safety hazards of at-home fetal dopplers before you use one.

A home fetal doppler can’t be used in place of a doctor’s appointment. In other words, they’re meant to be used in between visits to the doctor, not instead of visits to the doctor.

One of the reasons for this is because home fetal dopplers can be of poor quality. Think about it: Your doctor will always have medical-grade, accurate equipment, approved by any required safety agencies.

But practically any company can create a device (or perhaps worse — an app for a device), call it a doppler, and sell it online. There are no regulations for selling dopplers online, so this is a bit like the Wild, Wild West, folks. You can’t always be sure whether you’re getting an accurate and safe product.

More importantly, your doctor or midwife is trained to operate a doppler. They know what all the sounds mean — there’s a lot going on in there! — and they know what’s concerning (and what’s not).

Your healthcare provider is also best equipped to diagnose and treat any potential health issues. Not to mention, they can also be a source of support — which is great if you’re feeling nervous or if you have any questions.

While some brands claim that their fetal dopplers can detect heartbeats from 9 weeks into the pregnancy, others claim they only work from around week 16.

Some companies even state that their dopplers should only be used in the third trimester — that is, from week 28 onward. (And just a reminder: By this time, you should be feeling your baby kick and may even hear that little heart beating away with nothing but a good ol’ stethoscope.)

But we know what you’re really wondering — can any over-the-counter fetal dopplers work earlier than nine weeks? The short answer: We couldn’t find an up-and-up brand that claims this. However, anecdotally, many people say that they used their doppler before it was meant to pick anything up, and they managed to hear their little one’s heartbeat.

You may want to play around with your doppler and see if you can hear anything. Remember, it’s common to only hear the heartbeat from the second trimester onward, so it’s important to know yourself and know if not hearing it may cause you unnecessary worry.

While at-home fetal dopplers are appealing to many parents-to-be, there are some safety concerns.

In 2014, the Food and Drug Administration (FDA) advised against using fetal dopplers. The only time you should use a doppler, the FDA says, is when a doctor is using it, in which case it is medically necessary.

There isn’t any research that shows that ultrasounds are harmful, but it’s best to err on the side of caution when it comes to your baby’s health. As an FDA biomedical engineer explains, “Ultrasound can heat tissues slightly, and in some cases, it can also produce very small bubbles (cavitation) in some tissues.”

This is more worrying when it comes to at-home fetal dopplers, because some parents might want to reach for their fetal dopplers every day. Using it for a few minutes once a week shouldn’t cause any harm to your baby.

At-home fetal dopplers can also be potentially harmful because they can give you a false sense of reassurance, according to the United Kingdom’s National Health Service (NHS).

Along those lines, in 2009, an article in the British Medical Journal noted a case of a woman who was 38 weeks pregnant. She noticed that the baby moved less, but found a heartbeat through her fetal doppler, so she didn’t seek medical help. She had a stillbirth. It’s possible that she detected her own heartbeat or the vibration of the placenta.

While the stillbirth might have been unavoidable, the authors say, it’s a warning to all parents that fetal dopplers can’t replace your doctor’s expertise.

If you suspect something is wrong with your baby — for example, if they’re moving less, if you have unusual spotting, or if you have stomachaches — you can’t rely on an at-home fetal doppler to detect whether your baby’s OK. If you think something is wrong, see a doctor immediately. It’s possible for the baby to have a strong heartbeat even if something is wrong.

Remember, it’s always best to err on the side of caution and speak to medical professionals if you have any concerns — that’s what they’re there for!

Many people buy home fetal dopplers to soothe their anxiety about their pregnancy. They might want to “check in” on their baby in between doctor’s visits.

However, using a fetal doppler can produce the opposite effect. Being unable to find the heartbeat can cause a bit of panic. But there are real reasons for this difficulty. You might be unable to find your baby’s heartbeat if:

  • The device is broken. Given that some dopplers aren’t approved by any regulatory body, they don’t have to pass any standards and some are low quality.
  • You’re operating it incorrectly. This is possible because they were designed to be used by trained professionals.
  • It’s too early in the pregnancy to detect a heartbeat.
  • Baby has moved into a position that makes detection more difficult.

Most dopplers come with their own instructions for operating the device, but here is a general guide:

  1. Insert batteries into your doppler if you haven’t done so already.
  2. Lie back in a comfortable position.
  3. Lift up your top and move your pants down slightly.
  4. Apply the sonogram gel to your lower belly. (Don’t have sonogram gel? Understandable — not a lot of us have that just lying around the house! Aloe vera is a great alternative, and many lotions will work in a pinch.)
  5. Turn the doppler on and slowly — really slowly — move it around until you can hear the heartbeat. The earlier it is in your pregnancy, the lower you’ll likely have to go. Try below your belly button.
  6. Be aware that you’ll also hear your own heartbeat and the pulse of an artery. Baby’s heartbeat is much faster than either of these.

Fetal dopplers can be bought online. There are many brands out there that sell fetal dopplers, but — and this is a red flag in some cases — not that many are transparent about the details of their devices. Here are a couple of the more popular brands.

Note that Healthline recommends dopplers be used by medical professionals only.

Sonoline B

  • It’s one of the more popular and widely recommended brands by parents and parents-to-be.
  • It’s FDA approved, but only for use by a medical professional.
  • Package insert says it can be used from the 12th week of pregnancy. (Remember: Your results may vary.)
  • Screen shows baby’s heart rate as well as the device’s battery levels.
  • Built-in speaker has output for earphones or a recording device.

AngelSounds by Jumper

  • Package insert says it can be used from the 12th week of pregnancy.
  • The probe can be switched out.
  • It’s compact and easy to carry and it allows for headphones.
  • Some versions of the doppler have a screen to display information about the heartbeat, but some don’t.

Take care to avoid scams by purchasing from a reputable source. And while getting a cheaper fetal doppler can be tempting, the cheaper devices tend to have poorer reviews — so let the buyer beware!

The desire to use a fetal doppler at home is understandable — hearing that precious little heartbeat can be magical. But it’s important to be aware of the potential issues with fetal dopplers. Remember, you can’t rely on a device to diagnose any problems with you or your baby.

Keep up with your prenatal appointments, and follow your OB-GYN’s instructions for kick counting as baby’s big day approaches. You can also get your doctor’s opinion about using a doppler at home — never be afraid to ask questions that ease any pregnancy fears or jitters.