Comparison of Intrauterine and Postnatal Brain Magnetic Resonance Imaging: Systematic Review

Fetal magnetic resonance imaging (MRI) identifies brain abnormalities better than transabdominal ultrasound. Most studies compare fetal MRI with postnatal cranial ultrasound or postmortem, so it is unclear how useful postnatal MRI is after fetal MRI. This work aimed to review the literature on postnatal MRI compared with fetal MRI to determine whether it provided useful clinical information.

A literature search to April 2024 was performed to identify publications on fetal brain abnormalities examined using both fetal MRI and postnatal MRI. A systematic review was performed. The quality of research was evaluated using Joanna Briggs Institute checklists.

We identified 24 studies of 401 participants. All identified papers were retrospective or prospective case series at high risk of bias. Fourteen (58.3%) of the studies were high or moderate quality and 10 (41.7%) were low. Postnatal MRI confirmed the findings of fetal MRI in 296 (73.8%), refuted the diagnosis on fetal MRI in 24 (6.2%), and found additional abnormalities in 81 (20.2%). The suspected abnormalities on fetal MRI not confirmed on postnatal MRI were 12 isolated inferior cerebellar vermis hypoplasia, eight cerebellar vermis cysts, one mild ventriculomegaly, and one each of focal white matter abnormality, mega cisterna magna, and an unstated abnormality. Two papers including 17 participants reported that postnatal MRI changed the management or prognosis in nine (52.9%) participants.

The evidence on the value of postnatal MRI following a diagnosis of fetal brain abnormality is limited in size and quality, and further prospective research evidence is required.