Fetal brain injury in complicated monochorionic pregnancies: diagnostic yield of prenatal MRI following surveillance ultrasound and influence on prognostic counselling.

ObjectiveThis study aimed to determine the additional diagnostic information provided by prenatal (fetal) magnetic resonance imaging (pMRI) following tertiary ultrasound (US) for fetal cranial abnormalities in complicated monochorionic gestations. MethodsWomen with complicated monochorionic gestations complicated by twin-twin transfusion syndrome, co-twin demise (CD), selective intrauterine growth restriction, and/or twin anaemia-polycythaemia sequence who were referred for pMRI after tertiary US were included. Additional diagnostic information by pMRI that changed prognostic counselling was the primary outcome. ResultsThirty-three women with 48 live fetuses had pMRI at a median of 25weeks (range: 21-29). Three of ten survivors of spontaneous CD, one of eight survivors of CD after twin-twin transfusion syndrome and 1/30 co-survivors had diagnostic information added by pMRI that altered counselling; US was normal in two and in the other three underrepresented parenchymal injury (5/33=15%; 95% confidence interval 0.27-0.03). Additional findings included occipital lobe infarction, hemispheric injury, dural sinus thrombosis, ischaemia-producing polymicrogyria and intraventricular haemorrhage. Another 8/33 women had additional information provided by pMRI that did not alter counselling. ConclusionPrenatal magnetic resonance imaging resulted in changed prognostic counselling in 5/33 pregnancies. Evaluation of incorporation of pMRI into routine surveillance of complicated monochorionic gestations is needed. (c) 2017 John Wiley & Sons, Ltd.