MRI Safety During Pregnancy: Myths and Facts
Updated: 4 days ago
Is an MRI safe during pregnancy? When your doctor decides an MRI is needed, major medical groups consider it an acceptable test during pregnancy, because MRI uses a magnet and radio waves instead of radiation. Still, every scan during pregnancy should be a careful decision made with your doctor. If you are pregnant or think you might be, always tell your doctor and the MRI staff before your scan.
This guide clears up common myths, explains what is known and what is still being studied, and covers how to prepare if you need an MRI while pregnant.
Tell your doctor and the MRI staff first
This is the most important step. If you are pregnant, think you could be, or are trying to get pregnant, tell:
The doctor ordering your MRI, so they can weigh whether the scan is needed now or can wait
The scheduling staff, when you book your appointment
The technologist, on your safety form and again before the scan
Your doctor and the imaging team will decide together with you whether to go ahead, whether contrast dye should be avoided, and whether the scan should be done at a setting with obstetric support. Don't wait for someone to ask. Speak up.
Why MRI is often chosen during pregnancy
During pregnancy, doctors try to avoid tests that use ionizing radiation when another test can answer the question. Ultrasound is usually the first choice. MRI is often the next step when ultrasound doesn't give enough detail.
MRI does not use X-rays. It uses a strong magnetic field and radio waves to make detailed pictures of soft tissue. That makes it useful for questions about the brain, spine, belly, and pelvis. Learn more in our guide to why MRI scans use no radiation.
Some situations where a doctor may order an MRI during pregnancy include:
Belly pain when ultrasound can't give a clear answer, such as possible appendicitis
New nerve or brain symptoms, like weakness or certain types of headache
Back or spine problems that need a closer look
Questions about the placenta or uterus that ultrasound can't fully answer
Only your doctor can decide whether you need an MRI and when.
Myths and facts about MRI during pregnancy
Myth | Fact |
MRI uses radiation that can harm the baby. | MRI does not use ionizing radiation. It uses a magnet and radio waves. |
MRI must always be avoided in the first trimester. | Medical guidance does not ban MRI in any trimester when it is truly needed. Your doctor weighs whether it can wait. |
The noise from MRI damages the baby's hearing. | Harm to a baby's hearing from MRI has not been shown in human studies. Researchers continue to study it. |
MRI contrast dye is always fine during pregnancy. | Contrast dye reaches the baby, so doctors generally avoid it during pregnancy unless it is truly needed. |
An MRI means something is seriously wrong. | Doctors order MRIs for many reasons, often just to get a clearer picture than ultrasound can give. |
If I need an MRI, I should just wait until after the baby is born. | Delaying a needed test can be risky for both mother and baby. Let your doctor decide the timing. |
What medical guidelines say
Groups such as the American College of Obstetricians and Gynecologists (ACOG) and the American College of Radiology (ACR) have published guidance on imaging in pregnancy. In plain terms, that guidance says:
Ultrasound and MRI are the preferred imaging tests during pregnancy because they don't use ionizing radiation.
MRI has not been linked to harm to the baby when it is used for a clear medical reason.
A needed MRI should not be withheld, because the mother's health matters to the baby's health.
Contrast dye should be limited to cases where it clearly helps the mother's or baby's care.
These are general principles. Your doctor applies them to your situation.
What's still being studied
Being careful also means being honest about what isn't fully known. Researchers have looked at a few theoretical concerns:
Warmth: The radio waves can slightly warm body tissue. Scanners have limits to keep this low.
Noise: MRI is loud. Studies so far have not shown hearing harm to babies, but research continues.
Very early pregnancy: There is less data on scans early in pregnancy, which is one reason doctors think carefully about timing.
Because of these open questions, doctors usually order MRI during pregnancy only when the answer will help guide care. Many imaging centers postpone elective or screening scans, like full body screening, until after pregnancy. Ask your doctor if your scan can wait.
Contrast dye and pregnancy
Some MRI scans use a contrast dye called gadolinium, given through an IV. During pregnancy, this dye can cross the placenta and reach the baby. Doctors have not fully worked out what that means long term.
For that reason, contrast is generally avoided during pregnancy. It is only used when the doctor and radiologist agree it is needed to answer an important question. Many MRI scans don't need contrast at all. If your order includes contrast, make sure the ordering doctor knows you are pregnant.
What about breastfeeding?
Current medical guidance generally says breastfeeding does not need to stop after a gadolinium contrast MRI, because only a very small amount reaches breast milk and even less is absorbed by the baby. If you have concerns, talk with your doctor.
How to prepare for an MRI while pregnant
Confirm with your doctor that the scan is needed now and whether it includes contrast.
Tell the staff you're pregnant when you book and again when you arrive.
Dress without metal and leave jewelry at home.
Bring prior reports and your doctor's order.
Ask about comfort. Lying flat on your back for a long time can be uncomfortable later in pregnancy. Ask whether cushions or lying slightly on your side is possible.
Speak up during the scan if you feel dizzy, short of breath, too warm, or uncomfortable. The technologist can hear you the whole time.
You'll also get ear protection for the noise. For general tips, see our complete guide to what to expect before, during and after your MRI.
Frequently asked questions
Can I get an MRI while pregnant?
Many pregnant patients can have an MRI when their doctor decides it's needed. Always tell your doctor and the MRI staff that you are pregnant first, so they can decide together with you whether and when to scan.
Is MRI safe in the first trimester?
Medical guidance does not ban MRI in the first trimester when it is truly needed. But there is less data early in pregnancy, so your doctor will carefully weigh whether the scan can wait.
Is MRI safer than a CT scan during pregnancy?
MRI and ultrasound don't use ionizing radiation, so they're usually preferred. In some urgent cases, a CT may still be the right test. Your doctor will choose based on your situation. See MRI vs. CT scan.
Will I get contrast dye if I'm pregnant?
Usually not. Contrast is generally avoided during pregnancy and used only when your doctor and the radiologist agree it is needed.
Should I tell the MRI center if I might be pregnant?
Yes. Even if you're not sure, tell the staff and your doctor. They can help you decide on next steps before the scan.
Can I have an elective or screening MRI while pregnant?
Many centers postpone elective and screening scans until after pregnancy. Talk with your doctor about the right timing.
Related reading
Schedule an MRI at Millenium MRI
Millenium MRI has centers in Ocala, Largo, and Tamarac, Florida, and in North Little Rock, Springdale, Jonesboro, and Marion, Arkansas. If you are pregnant or might be, please tell us when you call so our team can review your doctor's order before your visit. Our board-certified radiologists read every scan, and results are usually sent to your doctor within 24 hours. We're open Monday through Friday, 9am to 5pm. Call your nearest center or request an appointment online.
This article is for general information and is not medical advice. Talk with your doctor about your specific situation.
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