If you’ve been pregnant before, you probably know what a fetal doppler is. But if you haven’t or in case you forget, let’s review quickly before we get into the evidence around and safety of use of commercially sold fetal doppler devices at home.
Disclaimer: this is not medical advice nor should it be interpreted as such. This post is for informational purposes only. Please discuss the use of a fetal doppler with your maternal healthcare provider.
What is a doppler?
Dopplers exist for more than just fetal monitoring, so in case you’ve been exposed to other types of dopplers in your life I think it’s important to discuss just what a doppler is in general because it’s sort of a funny word.
A doppler is a type of ultrasound that looks specifically at blood flow. It uses high frequency sound waves to do this. The reading of these sound waves (which bounce off red blood cells) can give your provider information about your blood flow speed and direction (depending on the type of doppler that is done – because there are multiple types). If blood isn’t flowing, there may be faint sounds or absence of sounds of flow and this often indicates some type of blockage.
You might have a doppler done for a variety of reasons or in different areas to check blood flow. For example, it is commonly used to check heart function or (and pregnant women might be familiar with this test in some cases) to check for a deep vein thrombosis (DVT) in the leg.
When is a fetal doppler used?
A fetal doppler is just a doppler that is used for fetal blood flow monitoring, or fetal heart rate. It is usually used after about 12 weeks of pregnancy (provider dependent) for the best accuracy.
You would lay down or recline, and the transducer or probe is placed on your belly with jelly. If you’ve been pregnant, you would know this well. At regular appointments the purpose is usually to check fetal heart rate and is usually displayed on a small device showing this.
Sometimes special testing using a doppler with imaging is done to look at umbilical artery blood flow.
Additionally, you may use some type of fetal monitoring during labor. Sometimes this is continuous and sometimes it is not (for example, for my home birth we did not have continuous monitoring but uses “hands on” listening but for my induction we use continuous). This is often a choice you can discuss with your provider in advance of labor, both options come with their own risks and benefits. Also, in some populations fetal monitoring is not as effective.
Hands on monitoring is an evidence-based option too though, but isn’t seen as much in practice often due to lack of health human resources. A good resource for some quick facts on both types of monitoring is available on this Evidence Based Birth handout and may help to give you more information in advance of a conversation with your provider.
The type of fetal doppler we are discussing in this post is the handheld device. You may have noticed that there are now fetal dopplers for sale for commercial use… they are not exactly the same as the ones your healthcare provider would use….
Fetal Dopplers at Home: Evidence, Safety & Risk Review
Current Recommendations & Health Safety
The current recommendation from the U.S. FDA is to avoid both the use of 3D/4D ultrasound for “keepsakes” (as in, you’re not having it done for a medical purpose) and to avoid the use of handheld fetal heartrate monitors at home if they are not recommended by your healthcare provider. They are actually on the market as prescription devices.
Fetal dopplers are considered to be safe devices when used by a trained professional or perhaps under the guidance of one (this is not explicitly stated, but their designation as a prescription device points to this assumption)- the right way and at the right “dose”. This is because, with all ultrasounds because they use sound waves, there is a risk for over heating and for the production of bubbles within some tissue.
The general recommendation from studies done in the past is for trained health professionals to use these devices in clinic the least amount possible (2001 study, 2012 study). Only as medically necessary and following guidelines. This would likely remain a recommendation for anyone using one under the guidance of their provider as well.
There is definitely a gap in the evidence around safety for home devices too – so, that is likely why the recommendation is to avoid their use especially without guidance, because we just don’t have the data to support using it at home being safe. The FDA also notes that the time and length of sessions with the doppler at home are uncontrolled. And there are demonstrated risks when ultrasound devices are not used properly that are still considerations.
Risks for Misinterpretation
The biggest safety risk with using a fetal doppler when you are not trained to do so can result in two forms of misinterpretation.
On one side of the spectrum, you could misinterpret something that is normal as abnormal, or you could simply misinterpret the reading/rate. This could happen to someone who is not trained/supported by their HCP or “prescribed” a fetal doppler. The risk here is additional anxiety, stress and potentially wasted visits to healthcare facilities.
The second form of misinterpretation is much more grave. This is misinterpreting abnormal as normal, or being falsely reassured. By for example, reading your own placental flow or pulse as babies. I read one account of a situation like this that very sadly resulted in loss of the baby (from the British Medical Journal which was from 2009) and one other they reported that resulted in a NICU stay and complications.
This is not meant to be a post to scare someone, but to highlight the risks of using a fetal doppler untrained or over the counter. The authors of the BMJ article that the case they reported from their unit may not have been avoided but that the device and the reassurance it falsely provided in the situation delayed the patient from going to the hospital.
What Are the Benefits?
There are still benefits, and I am sure any mother who has had a history of miscarriage or stillbirth, or even just perinatal anxiety can understand. Early pregnancy especially when movements aren’t 100% consistent, that time between 12-18 or 20ish weeks is very mentally consuming. You may not even feel pregnant! Or maybe your symptoms wax and wane, or those early symptoms have quieted…
And so you wonder, is there a baby in there? Is baby ok?
This is where the benefit from these devices can be seen. You obviously cannot pop in to see your provider everyday or every week. Your early appointments are spread out, so in most cases.. you don’t “hear” from or see baby for quite some time between visits. This is where the benefit is for those who are trained by their providers to use these devices under prescription. Reassurance. Mental comfort. Anxiety reduction. Despite the risks, we cannot deny that these benefits exist and that they may help some expecting parents immensely with the stress and anxiety of the earlier stages of pregnancy.
Question for Healthcare Providers: How do we support patients?
So my question here is – how do we balance risk and benefit? From a person-centered care perspective, we need to meet patients where they are and consider how past traumas impact their care experience. Stillbirth, miscarriage and loss are traumatic experiences there is no doubt. If a regulated version of the device can be prescribed, the person can be taught to use it, and it can provide comfort – could that be a possible avenue we as healthcare providers could explore?
It’s like a mental health day prescription with a little more work – because it really would help to support mental health. I’ve read many anecdotal accounts of women using them for comfort.. and similar to the argument on bed sharing (which I’ve written about extensively) if patients will do it anyways, should we not do our best to make it the most safe?
It would involve, from a policy level, ensuring that the devices available are functional and provide the right warnings regarding use.
From a clinical level, we would need to have the time and human resources (I know how problematic both these requests are at this time..) to teach.
But with person-centered care at the forefront, should this not be considered an important step in the right direction? To offer something like this? Or can we find a solution that is different but that offers the same level of comfort, safely?
Just something to think on. We have an issue – anxiety and trauma from past losses – how can we offer more supports to this group of expecting persons?
Because I know, again anecdotally, that they don’t have the support they need. The internet and social media are wonderful for providing a place for people to connect and support each other, but the healthcare system needs to do that too. We need to be there for our patients and work with them to create the best care experience they can have.
Thank you for coming to my TED talk…
Doppler Ultrasound – Stanford Medicine
FDA Doppler Ultrasound Statement
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