Outcome of Rare Fetal Septal and Callosal Anomalies: A Systematic Review and Meta-Analysis

Objectives: To report the outcome of isolated rare anomalies of the cavum septi pellucidum (CSP) and corpus callosum (CC), including obliterated CSP, septal agenesis, hypoplasia of the CC, pericallosal lipoma, thin and thick CC and wide and narrow CSP. Methods: Medline, Embase and Cochrane databases were searched. Inclusion criteria were studies reporting the outcome. The outcomes observed were genetic anomalies, associated anomalies detected exclusively at follow-up ultrasound, fetal MRI or post-natal imaging, and adverse neurodevelopmental outcomes. Random-effect meta-analyses of proportions were used to combine data. Results: Thirty-three studies (604 fetuses) were included; an isolated anomaly was reported at the time of the initial diagnosis in 394 fetuses. There was no abnormal karyotype in any of the anomalies explored in the present systematic review. Abnormal neurodevelopmental outcome was reported in 9.7% of children with obliterated CSP, 15.4% of those with isolated septal agenesis, 24.9% of those with hypoplastic CC, 33% of those with thin CC, 8.7% of those with wide CSP, and none of the cases with isolated pericallosal lipoma and tick CC. Conclusion: The outcome is generally favorable in cases of isolated obliterated CSP, pericallosal lipoma, wide CSP and tick CC, while the small number of included cases does not allow drawing a robust conclusion of fetuses presenting with thin CSP and narrow CSP.