[Early prenatal detection of trisomy 18 by transvaginal sonography].

A case of very early sonographic detection of trisomy 18 is presented. It is the second most common autosomal aneuploidy in newborns and the most common anomaly in stillborns. More than 130 features of this trisomy have been detailed. Combinations of findings highly suggestive of the diagnosis can be detected in early stages of pregnancy using transvaginal sonography. Identification of these anomalies may be an indication for early amniocentesis.