We performed MRI in 43 oligohydramnios pregnancies referred with US-suspected fetal malformations at a mean of 25.5 weeks’ gestation. MRI findings were correlated with US data and outcome measures.
MRI correctly diagnosed one normal fetus suspected to have posterior cephalocele. In the remaining 42 fetuses who had malformations involving their urinary systems (n = 36), brains (n = 23), bones (n = 4), hearts (n = 3), and hepatobiliary (n = 3), MRI confirmed US diagnosis in 25 fetuses (58.1%), and added US-occult findings in 14 (32.5%) that were mainly related to the brain, urinary and hepatobiliary system. In 2 fetuses (4.7%), MRI added findings but missed data correctly detected by US in another 2 fetuses. MRI missed fetal skeletal and cardiac function abnormalities correctly detected by US. MRI accurately detected multiple body system abnormalities that aided prenatal correct diagnosis of syndromes including Meckel Gruber (n = 15) and Joubert syndrome and related cerebellar disorders (n = 1).
MRI is valuable in evaluating suspected fetal malformations especially those related to brain and urinary system when ultrasound is inconclusive owing to oligohydramnios. Fetal MRI can add findings that may modify prenatal diagnosis.