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.

Zusammenfassung

Ziel: Die klinische Anwendung der fetalen Neurosonografie hat in den letzten Jahren deutlich zugenommen. In einer retrospektiven Studie wurde das Spektrum und die Inzidenz der verschiedenen Corpus-Callosum-Anomalie (CCA) Formen in einem Level-III-Zentrum untersucht.

Material und Methoden: Von 1999 bis 2012 wurden 48 907 Zweit- und Dritttrimester Untersuchungen durchgeführt. Es fanden sich 140 (0,29 %) Fälle mit CCA. Unterschieden wurde zwischen vollständiger oder partieller Corpus Callosum (CC) Agenesie, CC Hypoplasie sowie isolierten und nicht-isolierten Fällen.

Ergebnisse: Von den 140 CCA-Fällen zeigten 107 eine komplette Agenesie (76 %), 20 eine partielle Agenesie (14 %) und 13 ein hypoplastisches CC (9 %). Im Untersuchungszeitraum ergab sich ein kontinuierlicher Anstieg aller Typen von CCA über 3 Zeitintervalle (1999 – 2004: n = 26; 2005 – 2008: n = 32; 2009 – 2012: n = 82), wobei das Verhältnis zwischen isolierten und nicht-isolierten Fällen gleich blieb. Das mediane Gestationsalter bei Diagnose betrug 25,0 SSW und änderte sich in den Zeitintervallen nicht. Nur 29 % (41/140) der Fälle wiesen eine isolierte CCA auf, die restlichen 71 % (99/140) waren in 22,2 % mit zerebralen (22/99) und in 40,4 % mit extrazerebralen (40/99) Fehlbildungen assoziiert. Des Weiteren fanden sich in 21,2 % Aneuploidien (21/99) und in 16,2 % syndromale Erkrankungen (16/99). Alle bis auf einen Feten mit einer Aneuploidie hatten zusätzliche zerebrale oder extrazerebrale Fehlbildungen.

Schlussfolgerung: Der Anstieg der Diagnosehäufigkeit von CCA reflektiert die zunehmende Erfahrung in der fetalen Neurosonografie. Trotz des Anstiegs der absoluten Zahlen von Diagnosen veränderte sich das Verhältnis zwischen isolierten und komplexen Formen nicht. Aufgrund der häufig vielschichtigen Krankheitsbilder ist eine detaillierte fetale Beurteilung erforderlich.

Key words

corpus callosum - prenatal diagnosis - ultrasonography - central nervous system anomalies - fetal neurosonography

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