By Sarina Gomez
This article is general information, not medical advice. Ask your midwife, OB-GYN or sonographer about your own pregnancy and scans.
No study has shown that diagnostic ultrasound, including 3D and 4D, harms a developing baby. But the FDA, the American College of Obstetricians and Gynecologists (ACOG) and the American Institute of Ultrasound in Medicine (AIUM) all advise against scans done only for keepsake pictures, because ultrasound puts energy into tissue and its long-term effects aren’t fully known. The real question isn’t 3D versus 2D; it’s medical versus non-medical use, and who is holding the probe for how long.
The short answer: no proven harm, but “medical reasons only”
The medical bodies agree on two points at once. ACOG’s patient page on ultrasound exams says there is currently no evidence that ultrasound is harmful to a developing fetus, and no links have been found to birth defects, childhood cancer or developmental problems. The same page adds that effects could be identified in the future, so exams should be done only for medical reasons by qualified professionals, and “casual use of ultrasound during pregnancy should be avoided.”
The NHS says the same in plainer words: there are no known risks to the baby or the mother from a scan. And unlike X-rays, ultrasound does not use radiation, as RadiologyInfo (from the American College of Radiology and RSNA) notes.
So a keepsake scan is not known to be dangerous. It’s discouraged because “not known to be harmful” is different from “shown to be safe at any length, by anyone.”
What the FDA, ACOG and AIUM say, side by side
The three US bodies use different words for the same position. Here they are together:
| Organization | Position on ultrasound in pregnancy | On keepsake-only scans |
|---|---|---|
| FDA | Generally considered safe when used prudently by trained providers; it can heat tissue slightly and in some cases create small gas pockets (cavitation), and the long-term consequences are unknown | Use solely for keepsake videos “has been discouraged”; keepsake images are reasonable during a medically indicated exam if no extra exposure is needed |
| ACOG | Ultrasound and MRI “are not associated with risk” and are the imaging of choice in pregnancy, but should be used prudently and only to answer a clinical question | Casual use should be avoided |
| AIUM | Not enough evidence to conclude ultrasound causes harm in humans, but that is not proof harm is impossible; use minimal exposure | Non-medical use to view the fetus or see the sex is “inappropriate and contrary to responsible medical practice” |
Sources for each row: the FDA’s page on ultrasound imaging, ACOG Committee Opinion 723 and the AIUM statement on prudent use and safety (2020).
Why doctors worry when no harm is proven
The caution comes from three facts, not from a known injury.
Ultrasound is energy. The FDA describes two physical effects, slight heating and cavitation, and says operators should follow ALARA: exposure “as low as reasonably achievable.” Machines show this as the thermal index (TI) and mechanical index (MI), which the AIUM asks operators to watch.
The safety data are older than today’s machines. The AIUM points out that the human studies are based mainly on exposure before 1992, the year the acoustic output limits for fetal scanning were substantially raised. Some studies reported effects and others didn’t; none established a cause.
Keepsake studios are set up differently. The AIUM describes freestanding commercial “baby video” studios as usually having no physician review of the images and no regulation of the training of the person scanning. A medical scan, by contrast, ends in a report signed by a physician or advanced provider. In the US, the FDA notes that individual states regulate who may perform diagnostic ultrasound, so rules differ from state to state.
If you still book a keepsake scan: questions to ask
Many parents still choose a 3D or 4D session, and if you do, you can turn the guidance above into questions for the studio:
- Who will scan me, and what training do they have? The AIUM recommends fetal scans by trained, credentialed professionals. Ask about sonography credentials such as RDMS.
- Does a physician review the images? If not, the studio can’t tell you about anything medical, and you shouldn’t expect it to.
- What happens if you notice something unusual? Ask how they would refer you, and to whom.
- How long is the probe actually on my belly? A shorter scanning time means less exposure. Ask for the scanning time, not just the booked appointment length.
- Do you keep the output low? Ask whether they watch the TI, and whether they use Doppler just to play the heartbeat. The AIUM says spectral Doppler shouldn’t be used to document the heart rate unless there’s a clinical reason.
- Is the practice accredited? The AIUM keeps a directory of accredited practices on its website.
- Will this replace my medical scan? It shouldn’t. ACOG says every pregnancy should have at least one standard exam, usually at 18 to 22 weeks.
Timing matters for the pictures too; our guides to the best time for a 3D ultrasound and 3D vs 4D ultrasound cover what you’ll see when.
Lower-exposure ways to get a keepsake picture
The simplest keepsake comes from scans you’re already having. Both the FDA and the AIUM say keepsake images are reasonable when they’re produced during a medically indicated exam, and the AIUM encourages sharing images with patients. So ask at your dating and anatomy scans whether you can have a print or digital copy of a good profile view. The NHS notes that some hospitals charge for pictures, so check first.
Then make the most of the pictures you have. Our ultrasound keepsake ideas explain how to save printouts before they fade. And if you want to imagine the face, SeeMyBaby turns a photo of a scan you already have into an imagined newborn portrait in about a minute, with no extra time on the scanning table. It’s entertainment, not a medical reading; a clearer 3D or 4D profile gives a closer result. See how the ultrasound to baby portrait works.
Sources
- U.S. Food and Drug Administration: Ultrasound imaging
- American College of Obstetricians and Gynecologists: Ultrasound exams (FAQ); Committee Opinion 723, Guidelines for diagnostic imaging during pregnancy and lactation
- American Institute of Ultrasound in Medicine: Prudent use and safety of diagnostic ultrasound in pregnancy
- NHS: Ultrasound scans in pregnancy
- RadiologyInfo.org (ACR and RSNA): Obstetric ultrasound
More scan guides, including the 3D ultrasound guide and 4D ultrasound guide, are on the SeeMyBaby blog.
Questions parents ask
Are 4D ultrasounds safe for the baby?
A 4D scan is 3D images shown in motion, and the same guidance applies: no proven harm, but the FDA, ACOG and AIUM discourage scanning for keepsakes alone. If you book one, keep the scanning time short and choose trained staff.
Do 3D ultrasounds use radiation?
No. Ultrasound uses sound waves, not ionizing radiation like X-rays or CT scans.
How many ultrasounds are too many during pregnancy?
There’s no set number. ACOG recommends at least one standard exam, usually at 18 to 22 weeks, and more only when there’s a medical reason, done by qualified professionals.
Are home fetal heartbeat Dopplers safe?
The FDA says over-the-counter fetal heartbeat monitors should only be used by trained health care providers when medically necessary. Untrained use can mean longer exposure or a misread heartbeat.
Also available in: العربية · Español · Français · Italiano · 日本語 · 한국어 · Português (Brasil)
