MRI is an additional diagnostic tool that may be used to evaluate certain fetal conditions discovered on ultrasound. MRI and ultrasound are complimentary examinations, each having strengths and weaknesses. Ultrasound will be performed immediately before MRI to assess fetal activity and measure fetal size. The two examinations are interpreted together by a pediatric radiologist who specializes in fetal imaging.
Preparing for your fetal MRI
Because the MRI machine uses strong magnetic fields, patients must remove all jewelry and change into a hospital gown for the examination. Patients and accompanying family members are required to complete a questionnaire to screen for implanted metal that may be affected by the magnetic field.
The examination does not require the placement of an IV line. The patient will need to lie on their back or on their left side for 30-45 minutes while the images are being taken. Everyone in the MRI room will wear earplugs or headphones to protect from the loud noise the machine makes while obtaining images.
MRI is safe in pregnancy because it does not use ionizing (harmful) radiation. There have been no reports of adverse effects to the fetus or mother from diagnostic MRI.