Evaluation of prenatal diagnosis of associated congenital heart diseases by fetal ultrasonographic examination in Europe

Ultrasound scans in the mid trimester of pregnancy are now a routine parr o f antenatal care in most European countries. With the assistance of Registr ies of Congenital Anomalies a study was undertaken in Europe. The objective of the study was to evaluate prenatal detection of congenital heart defect s (CHD) by routine ultrasonographic examination of the Fetus. All congenita l malformations suspected prenatally and all congenital malformations, incl uding chromosome anomalies, confirmed at birth were identified from the Con genital Malformation Registers, including 20 registers from the Following E uropean countries: Austria, Croatia, Denmark. France, Germany. Italy, Lithu ania, Spain, Switzerland. The Netherlands, UK and Ukrainia. These registrie s follow the same methodology. The study period was 1996-1998, 709 030 birt hs were covered, and 8126 cases with congenital malformations were register ed. If more than one cardiac malformation was present the case was coded as complex cardiac malformation. CHD were subdivided into 'isolated' when onl y a cardiac malformation was present and 'associated' when at least one oth er major extra cardiac malformation was present. The associated CHD were su bdivided into chromosomal, syndromic non-chromosomal and multiple. The stud y comprised 761 associated CHD including 282 cases with multiple malformati ons, 375 cases with chromosomal anomalies and 104 cases with non-chromosoma l syndromes. The proportion of prenatal diagnosis of associated CHD varied in relation to the ultrasound screening policies from 17.9% in countries wi thout routine screening (The Netherlands and Denmark) to 46.0% in countries with only one routine fetal scan and 55.6% in countries with two or three routine fetal scans. The prenatal detection rate of chromosomal anomalies w as 40.3%, (151/375 cases). This rate for recognized syndromes and multiply malformed with CHD was 51.9% (54/104 cases) and 48.6%, (137/182 cases), res pectively: 150/229 Down syndrome (65.8%) were livebirths. Concerning the sy ndromic cases, the detection rate of deletion 22q11. situs anomalies and VA TER association was 44.4%, 64.7%, and 46.6%, respectively. In conclusion, t he present study shows large regional variations in the prenatal detection rate of CHD with the highest rates in European regions with three screening scans. Prenatal diagnosis of CHD is significantly higher if associated mal formations are present. Cardiac defects affecting the size of the ventricle s have the highest detection rate. Mean gestational age at discovery was 20 -24 weeks for the majority of associated cardiac defects. Copyright (C) 200 1 John Wiley & Sons, Ltd.