Fetal major anatomical defects are largely responsible for the high fetal and neonatal loss from this pathology.23 Fetal malformations are present in about 50% of cases of SUA and can affect any organ system. The comparison of sonographic and postnatal findings in cases of SUA syndrome has shown that minor malfor­mations of the musculoskeletal and cardiovascular systems or of the genitouri­nary tract are often misdiagnosed by ultrasonography, in particular when they are isolated.17 The discovery of a SUA in the perinatal period justifies a detailed ultra­sound examination of the neonate to exclude minor anomalies of internal organs such as the kidney or heart, which may lead to deleterious sequelae if untreated until late infancy. The antenatal discovery of a SUA together with another fetal structural abnormality should raise the question of antenatal chromosome inva­sive testing,23 in particular in early pregnancy24 when the diagnosis of structural defect is less accurate. However, it is most likely that, as for many other isolated fetal defects, an isolated SUA does not increase the risk for trisomy 21.17 Thus, the SUA is not a specific marker of chromosomal abnormalities and the higher incidence of SUA found in trisomies 13 and 1824 is probably only related to the higher incidence in these cases of major fetal defects which are known to be asso­ciated with the aplasia or atrophy of one of the umbilical arteries.