What Is Fetal Magnetic Resonance Imaging? Fetal magnetic resonance imaging (or fetal MRI) uses a magnetic field and radio waves to create detailed pictures of an unborn baby. This painless test does not expose the baby to radiation. Why Is a Fetal MRI Done? Doctors may order a fetal MRI to get more detailed images of a developing baby if a possible problem is seen on an ultrasound. The test can help look for problems in the brain, spine, bowel, lungs, and other body parts. How Should I Prepare for a Fetal MRI? You may be asked to either not eat at all, or to not have foods or drinks with sugar or caffeine for a few hours before your test. This can help keep your baby calm so that the MRI machine can capture clear images. You do not need a full bladder before this test. You cannot wear jewelry or any other items made of metal for the test, so it may be easiest to leave these at home. You may want to bring music that relaxes you to listen to during the test. What Happens During a Fetal MRI? A fetal MRI is usually done while you are lying down. If this is uncomfortable, the technician might be able to adjust your position a little to make you more comfortable, but still allow the machine to get the needed images. The MRI machine is noisy, but a fetal MRI is not painful. How Long Does a Fetal MRI Take? It usually takes 30 to 45 minutes to get the pictures needed. When Are the Results Ready? The doctor will review the fetal MRI and give you the results within 1 to 2 days. Are There Any Risks From a Fetal MRI? There are no known risks to you or your developing baby from a fetal MRI. Back to Articles Related Articles Prenatal Tests: First Trimester Find out what tests may be offered to you during the first trimester of pregnancy. Read More Prenatal Tests: Second Trimester Find out what tests may be offered to you during weeks 13 through 26 of pregnancy. Read More Prenatal Tests: Third Trimester Find out what tests may be offered to you during weeks 27 through 40 of pregnancy. Read More Prenatal Test: Ultrasound A prenatal ultrasound is a safe and painless test that shows a baby's shape and position. It can be done in the first, second, or third trimester of pregnancy. Read More Prenatal Tests: FAQs Every parent-to-be hopes for a healthy baby, but it can be hard not to worry. Find out what tests can keep you informed of your health — and your baby's — throughout pregnancy. Read More Fetal Echocardiogram A fetal echocardiogram (also called a fetal echo) uses sound waves to create pictures of an unborn baby's heart. Read More Magnetic Resonance Imaging (MRI) Magnetic resonance imaging (MRI) is a safe and painless test that uses a magnetic field and radio waves to produce detailed pictures of the body's organs and structures. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.