Post‐mortem confirmation of fetal brain abnormalities: challenges highlighted by the MERIDIAN cohort study

Objectives To assess and analyse the concordance between post-mortem findings and in utero MR imaging in the MERIDIAN cohort. Design Prospective cohort study SETTING: Fetal medicine units in the United Kingdom POPULATION: Pregnant women with a diagnosis of fetal brain abnormality identified on ultrasound at 18 gestational weeks or more METHODS: All pregnancies from the MERIDIAN study that resulted in abortion were included and the rate of uptake and success of the post-mortem examinations were calculated. In the cases in which diagnostic information about the fetal brain was obtained by post-mortem the results were compared with the diagnoses from iuMRI. Main outcome measures Outcome reference diagnosis from post mortem examination RESULTS: 155/823 (19%) pregnancies ended in abortion and 71 (46%) had post-mortem brain examinations of which 62 were diagnostically adequate. Hence the overall rate of successful post-mortem investigations was 40% and in those cases there was a concordance rate of 84% between iuMRI and post-mortem. Detailed information is provided when the results of the post-mortem and the iuMRI study were discrepant. Conclusion We have shown tissue-validation of radiological diagnosis is hampered by a low rate of post-mortem studies in fetuses aborted with brain abnormalities, a situation further compounded by a 12% rate of autopsy being technically unsuccessful. The agreement between iuMRI and post-mortem findings is high but analysis of the discrepant cases provided valuable clues to how providing information to parents can be improved.