The use of a fetal doppler in pregnancy can give valuable information to both you and your medical provider. But does using a ultrasound or a fetal doppler “for fun” pose any dangers to baby, and if so, are there any alternatives?


As a very basic explanation, a doppler is a form of ultrasound (much lower in megahertz than the ultrasound used by an ultrasound tech at your 20-ish week anatomy scan) which uses sound waves to relay information to the user. In the case of a doppler, the sound wave is producing the heartbeat of your baby for you and your provider to hear. While the heart beat provides you a sense of “all is well”, the heartbeat tells your provider how your baby is doing in that 1-min or so time frame. They’re listening for arrhythmia—which aren’t uncommon—accelerations in the heart rate, and will, over time, establish a baseline for your baby.

Most fetal heartbeats can be heard starting at 12 weeks, sometimes as early as 10 weeks. Baby’s position, placental position, and the amount of tissue on your abdomen can all effect when the heartbeat can be heard. It is becoming more and more common for soon-to-be parents to purchase or rent their own fetal doppler to use at home so they can have reassurance in between their monthly appointments with their provider. Not being able to feel baby move yet can also be a determining factor for purchasing or renting a doppler for home use. 


Some providers may tell you that ultrasounds (dopplers and diagnostic ultrasounds such as a 20-week anatomy scan, or higher level scans ordered by Maternal Fetal Medicine, MFM) are safe and pose no or very little risks to your baby, and they may be right. There is no evidence from human studies that show adverse effects on a human fetus. They likely see that the benefits of the ultrasound outweigh the (very minimal if not moot, in their eyes) risks. The CDC states that “ultrasound imaging has been used for over 20 years and has an excellent safety record.” The CDC goes on to acknowledge biological effects on the body, and that ultrasound for non-medical purposes is discouraged, but that “keepsake images or videos are reasonable if they are produced during a medically-indicated exam, if no additional exposure is required.”

Risks of prenatal ultrasounds are detailed in a book by Jim West: 50 Human Studies in Utero, Conducted in Modern China Indicate Extreme Risk for Prenatal Ultrasound. Without getting into too much detail, the studies found that ultrasounds do, in fact, have negative impacts. 

A word of caution if you decide to read this book on your own (which I encourage. It’s less than $10 on Amazon). The studies were done in China, on fetuses whose carriers were planning an elective abortion. The ultrasounds were performed before the elective abortions were performed (which is common practice before any abortion), and then the fetal tissues were examined after the abortion. 

The studies conclude that “Diagnostic Ultrasound [DUS] causation or initiation for Autism Spectrum Disorder (ASD), ADHD, personality anomalies, ophthalmological diseases, various malformations, skin diseases, and allergies. While DUS causation can be argued in isolation, there is the very real practical concept of toxic synergy. It should be argued that DUS initiates vulnerabilities to secondary stressors such as vaccines, or other pharmaceuticals. This conforms with the views of some mothers who record every detail of their child’s birth and development, and see their children autistic at birth or triggered autistic by vaccines or other pharmaceuticals. This concept, as a causation theory, is supported by ultrasound synergy studies….”

Professor Ruo Feng summarized the CHS (Chinese Human Studies) findings by saying “We need to reiterate that in obstetric ultrasound, diagnostic techniques should carefully adhere to a cautious scientific attitude. Specifically, abide by following these five points:

  1. Ultrasound should only be used for specific medical indications.
  2. Ultrasound, if used, should strictly adhere to the smallest dose principle, that is, the ultrasonic dose should be limited to that which achieves the necessary diagnostic information under the principle of using intensity as small as possible, the irradiation time as short as possible. 
  3. Commercial, educational fetal ultrasound imaging should be strictly eliminated. Ultrasound for the identification of fetal sex and fetal entertainment imaging should be strictly eliminated. 
  4. For the best early pregnancy [1st trimester], avoid ultrasound. If unavoidable, minimize ultrasound. Even later, during the 2nd or 3rd trimester, limit ultrasound to 3-5 minutes for sensitive areas, e.g., fetal brain, eyes, spinal cord, heart and other parts.
  5. For every physician engaged in clinical ultrasound training, their training should include information on the biological effects of ultrasound diagnostic dose safety knowledge. 

So where does this leave us? More importantly, where does this leave you? It’s your call. Best practice would be to limit exposure to ultrasound, unless medically necessary. Though….I think we can all agree that what is “medically necessary” to you might not be deemed “medically necessary” to another person. You and your trusted provider can have the discussion and decide. That decision may lead you to use a fetal doppler at each appointment and just one 20-ish week anatomy scan. Maybe you’ve been nursing your toddler and don’t know when you conceived, so an early 1st trimester dating scan is ordered by your provider. Maybe you have early bleeding and your provider orders an ultrasound to check on baby and where the placenta is to try and pinpoint the cause of the bleeding. Perhaps your first born had a genetic anomaly such as a cleft lip and you are concerned about baby #2 having the same so your provider orders a higher level ultrasound to rule out another cleft lip. 

Your pregnancy journey may warrant the use of several ultrasound scans, or just a few. If you’re concerned about exposure there are a few things you can do.

Fetoscope or Pinard Horn

If you’re seeing a conventional provider (OB or midwife) who delivers at a hospital, they may be reluctant to use, or they may not even have a fetoscope or Pinard Horn. These work just like a regular stethoscope except the cone or bell shaped end is what magnifies the fetal heart beat. They rely on the user placing the cone portion on the area in which they suspect baby’s back to be. You can usually hear baby’s heartbeat via a fetoscope around 20 weeks. Is a doppler is your only option at prenatal visits? Request heart tone checks be just long enough for your provider to hear what they need to hear. If you have a copper for home use, consider swapping it out for a fetoscope or Pinard Horn.

Movement is Reassuring

Relying on baby’s movement pattern is a great indication of well-being. The type of movement your baby makes will change over the course of your pregnancy, but the movements shouldn’t stop (unless baby is sleeping). Quick fast jabs to your ribs will change over to slower movements that feel like your baby is rolling over. This is normal and expected because your baby is running out of room.

Limit Entertainment Ultrasounds

It can be very tempting to splurge and get a 3D/4D ultrasound—and if you’re comfortable with the idea, then treat yourself. Chances are you’ll cherish the photos and the fun experience for years to come. 

Pregnancy is your first lesson in parenting and many of our clients jokingly (but also seriously) tell us they did more research during pregnancy than they *ever* did in college. You’re no longer making choices for just yourself, but your baby too. Where ever your pregnancy and parenting journey takes you….remember, we’re here for you!

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