A private ultrasound, often marketed as a “keepsake” or 3D/4D scan, is a non-diagnostic procedure chosen by expectant parents primarily for bonding and entertainment. These sessions are performed outside of medical necessity or a physician’s referral, typically in commercial storefronts. The increasing popularity of these elective scans has raised questions regarding their safety, particularly concerning exposure to sound waves without a medical purpose. This article investigates the scientific basis of ultrasound safety and the regulatory position on these elective procedures.
Understanding Ultrasound Technology and Safety Metrics
Ultrasound technology creates images of internal body structures by transmitting high-frequency sound waves into the body and recording the returning echoes. While this technology is generally considered safe when used appropriately, the energy emitted has the potential for two main biophysical effects on tissue.
The thermal effect involves a slight heating of the tissue as it absorbs the acoustic energy. This potential for temperature rise is estimated by the Thermal Index (TI), which is displayed on the ultrasound screen.
The mechanical effect relates to the potential for creating small, oscillating gas bubbles within the tissue, a phenomenon called cavitation. The potential for mechanical effects is measured by the Mechanical Index (MI). Both the TI and MI serve as real-time indicators for the operator, signaling the level of energy output and the risk of tissue interaction. Safety protocols dictate that exposure duration should be kept brief and the acoustic output should be the lowest level necessary to achieve an image.
Key Differences Between Medical and Elective Ultrasounds
The primary distinction between a medical and an elective ultrasound lies in its objective and operational protocol. A medical ultrasound is performed solely for a targeted medical reason, such as assessing fetal growth, anatomy, or placental location. Elective scans are performed for non-medical reasons, focusing on obtaining keepsake images or determining gender.
Diagnostic procedures strictly adhere to the ALARA principle, meaning the acoustic power and exposure time are kept “As Low As Reasonably Achievable” to gain the necessary medical information. The typical duration for a diagnostic scan is kept to a minimum, often under 10 to 15 minutes for a specific task.
Elective 3D and 4D scans, however, often require longer sessions, sometimes running for 20 to 45 minutes, as the focus is on capturing clear, aesthetically pleasing images. To generate high-quality, three-dimensional images, the ultrasound equipment is frequently operated at a higher acoustic output intensity. This practice results in elevated Thermal Index and Mechanical Index values compared to standard, two-dimensional diagnostic scans.
Furthermore, medical ultrasounds are performed by certified professionals, such as Registered Diagnostic Medical Sonographers (RDMS), who are trained to interpret complex medical findings and manage equipment settings safely. Many commercial keepsake facilities do not mandate the same level of medical certification or physician oversight for their operators.
Current Regulatory Guidance and Recommendations
Major health organizations have established positions cautioning against the use of ultrasound for non-medical purposes. The U.S. Food and Drug Administration (FDA) views the promotion and use of diagnostic ultrasound equipment for keepsake videos as an unapproved use of a medical device. They have advised that individuals who use a prescription device, like an ultrasound machine, without a physician’s order may be violating state or local regulations.
The American Institute of Ultrasound in Medicine (AIUM) discourages the non-medical use of ultrasound for entertainment or psychosocial purposes. The AIUM states that using ultrasound without a medical indication, even just to view the fetus or determine gender, is inappropriate and contrary to responsible medical practice.
This guidance is based on the fact that the long-term biological effects of prolonged or repeated exposure, particularly with higher output settings, are not fully known. These professional bodies emphasize that any fetal ultrasound should only be performed by appropriately trained and credentialed medical professionals who can weigh the medical benefit against the risk.
Mitigating Risk When Choosing a Private Provider
For individuals who choose to pursue an elective scan despite official warnings, several steps can be taken to minimize potential risk. It is prudent to verify that the technician holds a recognized professional certification, such as from the American Registry for Diagnostic Medical Sonography (ARDMS). This certification indicates the operator has met high standards for technical competency and safety knowledge.
Consumers should also confirm that the private facility operates under the supervision of a licensed physician, even if the physician is not physically present. During the procedure, the session duration should be limited to the minimum time required to capture the desired image. Requesting that the technician display the Thermal Index and Mechanical Index values and confirming they are kept as low as possible provides an additional layer of caution.