In vivo Assessment of Placental and Brain Volumes in Growth Restricted Fetuses With and Without Fetal Doppler Changes Using Quantitative 3D MRI

OBJECTIVE: The relationship between placental and fetal brain growth is poorly understood, and difficult to assess. The objective of this study was to interrogate placental and fetal brain growth in healthy pregnancies and those complicated by fetal growth restriction (FGR). STUDY DESIGN: In a prospective, observational study, pregnant women with normal pregnancies or pregnancies complicated by FGR underwent fetal MR imaging. Placental, global and regional brain volumes were calculated. RESULTS: 114 women (79 controls and 35 FGR) underwent MR imaging (median GA 30 weeks, range 18 –39). All measured volumes increased exponentially with advancing GA. Placental, total brain, cerebral and cerebellar volumes were smaller in FGR compared to controls (p<0.05). Increasing placental volume was associated with increasing cerebral and cerebellar volumes (p<0.05). CONCLUSION: Quantitative fetal MRI can accurately detect decreased placental and brain volumes in pregnancies with FGR and may provide insight into the timing and mechanisms of brain injury in FGR.