Abstract

Objectives To provide further evidence on the outcomes associated with fetal malformations of cortical development (MCD), currently informed by data from symptomatic paediatric cohorts, this study provides a new classification system. Design Multicentre retrospective cohort study. Setting Fetal medicine units of three tertiary centres in the United Kingdom and Italy. Population 118 foetuses diagnosed with MCD by ultrasound and/or magnetic resonance imaging included. Methods The cases were classified according to their presumed aetiology (genetic, haemorrhage, dysgenesis, infection) and imaging findings (focal, diffuse, mantle, sulcation). Neurodevelopmental delay was classified as mild, moderate or severe. Cases with missing information on postnatal outcome were excluded. Main Outcome Measures Postnatal neurodevelopmental outcome ascertained from the infant's neurological assessments according to international performance scales, depending on the age. Results There were 52/118 (44%) livebirths, 64/118 (54.2%) terminations of pregnancy (TOP) and 2/118 (1.6%) intrauterine demises. Twenty‐five of 46 cases (54.3%, 95% CI 39–69.1) that survived the neonatal period had a normal or mildly delayed neurological development. The commonest aetiology was genetic, and the most frequent radiological finding was reduced sulcation. The best neurological outcome was found in children with focal lesions; those with diffuse hemispheric lesions had the worst one. Conclusion This is the largest cohort of foetuses diagnosed with MCDs systematically classified by aetiology and radiological findings. In this retrospective cohort of liveborn survivors, over half had normal or mildly abnormal neurodevelopmental outcomes. Prognosis varied according to lesion pattern and suspected aetiology. Fetal MCDs in this study had better neurodevelopmental outcomes than previously reported, though findings should be interpreted with caution given selection and follow‐up limitations.