Prenatal Diagnosis of Anomalies of the Corpus Callosum over a 13-Year Period

Abstract

Purpose: The clinical use of detailed fetal neurosonography has increased over the past decade. This retrospective study explored the spectrum and frequency of different forms of corpus callosum anomalies (CCAs) in a level III center setting. Materials and Methods: Between 1999 and 2012, 48 907 detailed second and third trimester scans were performed. Among them, 140 (0.29 %) cases of CCA were diagnosed. We differentiated between complete and partial agenesis, hypoplastic corpus callosum (CC) and isolated and non-isolated forms. Results: The 140 cases with CCA included 107 with complete agenesis (76 %), 20 with partial agenesis (14 %) and 13 with a hypoplastic CC (9 %). Of them, 29 % (41/140) were isolated and 71 % (99/140) were non-isolated cases. Analysis of three time periods demonstrated an increase in the diagnosis of all types of CCA (1999 - 2004: n = 26; 2005 - 2008: n = 32; 2009 - 2012: n = 82), whereas the ratio between isolated and non-isolated types remained stable. The median gestational age at diagnosis was 25.0 weeks and did not change over the years. Non-isolated forms were associated with additional non-chromosomal cerebral anomalies in 22.2 % (22/99), extracerebral non-chromosomal malformations in 40.4 % (40/99), aneuploidies in 21.2 % (21/99), and syndromes in 16.2 % (16/99). All aneuploid fetuses except one showed cerebral or extracerebral malformations. Conclusion: The rise in prenatal diagnosis of CCA reflects the increased use of systematic fetal neurosonography over the years. Despite an overall increase in diagnosed cases, the relationship between isolated CCAs and complex forms remained stable. Since the percentage of coexisting anomalies is high, a detailed assessment by a specialist is recommended.