This handout explains the use of MRI in pregnant patients and what to expect.
While there are no known risks of using MRI in pregnant patients, it is only used when needed. MRI is safer for the fetus than x-rays or a CT scan. If you are pregnant and your doctor wants you to have an MRI scan, there is a chance that your doctor is concerned about your health or the health of your baby.
Your doctor may order an MRI if you have symptoms that need to be treated or your exam results are unclear and cannot wait until after the baby is born.
Ultrasound (US) is the scan used most often when pregnant and is often used to see the baby in the womb. If the US does not give a clear answer, or other parts of your body need to be viewed, an MRI will likely be done.
MRI does not use x-rays. It uses radio waves and a magnet to take pictures. Your scan will focus on a certain body part, such as the uterus/placenta, the baby in the pelvis, the brain or the spine. The time it takes to scan depends on the body part being looked at. For most exams you will need to lie still for 30-60 minutes.
For some MRI scans, we give you a contrast through an IV in your arm. While contrast helps get better pictures, we often will do the scan without contrast if you are pregnant. The decision to use contrast is saved for times when the care of the mother or fetus is in danger if it is not used. A radiologist will explain why they feel it is needed and the risks and benefits of using contrast. After they talk with you, we will ask you to sign a consent form. We only need written consent for MRI scans done with contrast.
Your health and safety are important to UW Health. Please let us know if you have any questions.