Prenatal detection of congenital heart disease-results of a Swedish screening program 2013-2017

Background This report evaluates results of a screening program on prenatal detection of congenital heart defects in a geographical cohort of western Sweden between January 1st, 2013 and June 31st, 2017. During the study period 88,230 children were born in VGR. Methods Retrospective data on pregnant women from the Vastra Gotaland region that were referred to fetal cardiologists in Gothenburg were retrieved. To determine prenatal detection rate, all neonates who underwent surgery or catheter intervention for a critical congenital heart defect born between January 1st, 2014 and December 31st, 2016 were included. The four-chamber view was implemented into the routine scan in 2009 and implementation of the ISUOG guidelines, including the outflow tracts, started in the region in 2015. Results 113 fetuses received a prenatal diagnosis of a major congenital heart defect. 89% of these were referred because of a suspected cardiac malformation and 88% were diagnosed before 22 completed weeks. 59% of the patients diagnosed before 22 completed weeks opted for termination of pregnancy. During 2014-2016, 61 fetuses had a prenatal diagnosis of a critical congenital heart defect and a further 47 were diagnosed after birth, hence 56% were diagnosed prenatally, 82% for those which had a combination with an extracardiac abnormality and/or chromosomal aberration compared to 50% if an isolated critical congenital heart defect was diagnosed. For single ventricle cardiac defects such as hypoplastic left heart syndrome, double inlet left ventricle and tricuspid atresia, the detection rate was 100%. The detection rate for transposition of the great arteries and coarctation of the aorta was 9 and 18% respectively. Conclusions 56% of all fetuses with a critical congenital heart defect were diagnosed prenatally during 2014-2016 and approximately 53% of all major congenital heart defects 2013-2017 as compared to 13.8% in 2009 in the same region. An increased focus towards the fetal heart in the routine scan improved the prenatal detection rate of major congenital heart defects. The detection of congenital heart defects affecting the four-chamber view seems sufficient, but more training is needed to improve the quality of the examination of the outflow tracts.