Diffusion MRI brain findings in neonates exposed to chorioamnionitis: a case series

The primary objective of this study was to determine the feasibility of using diffusion-weighted magnetic resonance imaging (DWMRI) to assess white matter changes in high-risk neonates. Secondary objectives were to determine if exposure to chorioamnionitis (clinical or histopathologic) is associated with DWMRI findings in the neonatal brain, and to calculate the sample size required for a more definitive prospective cohort study.

Seventeen women with PPROM (preterm premature rupture of the membranes) who delivered 18 infants not requiring ventilatory support were recruited to participate in this case series. When stable, infants underwent DWMRI scanning. All placentas were examined for evidence of histopathologic chorioamnionitis (HCA).

There was histopathologic evidence of chorioamnionitis in seven of the 18 placentas examined; three of these patients had clinical chorioamnionitis. Diffusion MRI revealed changes in both the diffusion-weighted imaging and the apparent diffusion coefficient in three of the seven infants confirmed to have HCA (43%), while only one of the 11 infants with normal placentas (9%) showed similar findings. Routine head ultrasound examination demonstrated abnormal cortical findings that would normally prompt further investigation in only one of these infants.

Exposure to HCA may be associated with abnormal DWMRI findings on imaging of the neonatal brain within 96 hours of delivery. Further study is required to delineate the association of chorioamnionitis and white matter changes with long-term neurodevelopmental sequelae.