Incidence and types of congenital cardiovascular malformations in Japanese trisomy 21 fetuses around 20 weeks

Abstract

ABSTRACT In order to clarify the incidence and types of cardiovascular malformations in Japanese trisomy 21 fetuses, seventeen cases were investigated at around 20 weeks of pregnancy. Cardiovascular malformations were observed in 8 of 17 cases (47.1%). The incidence of cardiovascular malformations was not greatly different from the estimated incidence (50%) in Japanese children with Down syndrome. The preferential elimination would not exist in trisomy 21 fetuses around 20 weeks relevance to cardiovascular malformations. Atrioventricular (AV) septal defect, tetralogy of Fallot and Ebstein's anomaly were observed in one case each. Bicuspid aortic valve and abnormal branching of the aortic arch were present in three and two cases, respectively. AV septal defect, which is perceived as a specific malformation of trisomy 21, was not recognized in high frequency in the present fetal study. A 13‐week‐old fetus showed multiple malformations; AV septal defect, tetralogy of Fallot and dysplastic bicuspid aortic valve. This case displayed an early morphology of AV septal defect which has rarely been reported in trisomy 21 fetuses. Possible pathogenesis of AV septal defect was discussed in relation to animal models of human trisomy 21. The present study indicated