A fetal ultrasound allows doctors and parents to take a peek at what’s happening inside the uterus. Doctors typically order ultrasounds at specific points throughout pregnancy to monitor the baby’s growth and development.
For-profit organizations also offer keepsake ultrasound videos, including 3-D and 4-D techniques that allow expectant parents to see detailed images of their developing baby. At-home fetal Doppler devices, which allow parents to listen for their baby’s heartbeat, have also become increasingly popular.
Naturally, you may be concerned about the safety of fetal Dopplers and ultrasounds. Understanding how these devices work, their potential risks, and when they’re medically necessary can help you make informed decisions during pregnancy.
What Is a Fetal Doppler, and How Does It Work?
An ultrasound uses high-frequency sound waves to produce an image of the baby growing inside your uterus. It sends sound waves into the body, which then bounce back from the developing baby and surrounding tissues. A computerized system translates this feedback into an image.
A fetal Doppler uses similar ultrasound technology, but its primary purpose is different. Instead of producing detailed images, a handheld fetal Doppler detects movement associated with blood flow, allowing healthcare providers to monitor the baby’s heartbeat.
While both technologies use sound waves, standard prenatal ultrasounds and fetal Doppler heartbeat monitors serve different purposes.
Are Ultrasounds and Fetal Dopplers Safe During Pregnancy?
Diagnostic ultrasounds have been performed for many years and have an established record of safety when used appropriately by trained medical professionals.
According to the U.S. Food and Drug Administration (FDA), ultrasound imaging does not use ionizing radiation, unlike X-rays. However, ultrasound energy can produce biological effects, including slight heating of body tissues.
Although no confirmed harmful fetal effects have been established from appropriately performed diagnostic ultrasound examinations, unnecessary or prolonged exposure should still be avoided.
Health Canada also emphasizes that diagnostic fetal ultrasound should be performed when the expected medical benefits outweigh any foreseeable risks.
At-home fetal Doppler monitors raise additional concerns. Parents without medical training may mistake their own heartbeat or blood flow for the baby’s heartbeat, potentially creating false reassurance when medical attention is needed.
For these reasons, health authorities recommend that fetal ultrasound devices be used for medical purposes by appropriately trained professionals.
Why Do Doctors Perform Ultrasounds During Pregnancy?
Your doctor may perform an initial ultrasound to confirm your pregnancy and estimate the baby’s gestational age.
It’s important to get an accurate estimate of gestational age to track the proper stages of development and schedule prenatal testing at the appropriate times.
An ultrasound can also help identify certain physical abnormalities or developmental concerns, allowing parents and healthcare professionals to prepare for any additional care their baby may need.
Later in pregnancy, a doctor might use an ultrasound to verify the position of the baby, check growth, or evaluate the placenta and amniotic fluid.
The number and timing of ultrasounds vary depending on your pregnancy and medical history. Some expectant mothers require additional scans to monitor specific health concerns.
Understanding the ALARA Principle for Ultrasound Safety
According to the American Institute of Ultrasound in Medicine (AIUM), ultrasound examinations should be performed by appropriately qualified healthcare professionals following established patient safety standards.
One important safety guideline is the ALARA principle.
ALARA stands for “as low as reasonably achievable.”
Because ultrasound energy has the potential to affect tissues, practitioners should use the lowest ultrasound output and shortest examination time necessary to obtain the required medical information.
This principle helps minimize unnecessary fetal exposure while allowing healthcare professionals to gather important diagnostic information.
The ALARA principle is particularly important when using Doppler ultrasound modes, which may involve higher acoustic output than standard imaging.
Are 3-D, 4-D, and Keepsake Ultrasounds Safe?
While it may be exciting to receive a keepsake video of your ultrasound or catch a glimpse of what your baby might look like, medical organizations discourage ultrasound examinations performed solely for entertainment.
The FDA advises against nonmedical keepsake ultrasound sessions because they expose the developing baby to ultrasound energy without providing a medical benefit.
Three-dimensional ultrasounds create detailed still images, while 4-D ultrasounds display moving 3-D images. These technologies can be useful in certain medical situations, but additional scanning purely for keepsake purposes is not recommended.
Health Canada also discourages fetal ultrasound performed solely for keepsake videos, noting that these sessions provide no information about the baby’s health.
If you’d like an ultrasound picture to remember your pregnancy, ask your healthcare provider whether images can be provided during a medically necessary examination without extending the scan.
Should You Use an At-Home Fetal Doppler?
At-home fetal Dopplers may seem like a reassuring way to check on your baby between prenatal appointments, but they aren’t a substitute for professional medical monitoring.
Finding a heartbeat doesn’t necessarily mean that your baby is healthy, and difficulty finding one doesn’t always indicate a problem.
If you’re concerned about your baby’s movements, heartbeat, or well-being, contact your healthcare provider promptly rather than relying on a home monitoring device. Reduced or changed fetal movements should be assessed even if you can hear a heartbeat.
The Bottom Line on Fetal Doppler Safety
Ultrasounds and fetal Dopplers can provide valuable information about your baby’s development and well-being when used appropriately.
Medical ultrasound has a strong safety record, but unnecessary exposure should be avoided. Following your healthcare provider’s recommendations is the best way to ensure that ultrasound examinations are performed when needed and with appropriate precautions.
Medical note: This article is intended for general educational purposes and should not replace advice from your obstetrician, midwife, or other qualified healthcare professional.
Originally published September 30, 2010, by ModernMom Staff. Updated October 30, 2026, to reflect current medical guidance and safety recommendations regarding fetal Dopplers and prenatal ultrasounds.
