[Prenatal diagnosis of conotruncal heart diseases. Results in 337 cases].

Prenatal diagnosis of conotroncal disease has developed by examination of the great arteries during morphological foetal ultrasonic scanning in the second term of pregnancy. This study reports the results of a series of 337 of these malformations diagnosed in the foetus over five and a half years. Their incidence with respect to all foetal cardiac malformations is 16.2%. Tetralogy of Fallot and pulmonary atresia with ventricular septal defect make up 56% of these cases, vascular malposition 16%, coarctation with or without interruption of the aortic arch 14%, truncus arteriosus 9% and agenesis of the pulmonary valves 5%. A karyotypic anomaly was found in 28 cases (8.2%) and, in the foetus with a normal standard karyotype, deletion of chromosome 22q11 was identified in 54 out of 237 cases. There was an associated polymalformative syndrome in 29 cases (8.3%). The training of obstetricians has increased the number of antenatal diagnoses of conotroncal abnormalities. Prenatal counselling should be given by a pluridisciplinary team because the association of these malformations with chromosomal abnormalities or with syndromes difficult to diagnose is common.