Fetal congenital heart diseases: Diagnosis by anatomical scans, echocardiography and genetic tests

Objective: To determine the distribution of major fetal congenital heart diseases (CHDs) diagnosed antenatally during routine second -trimester obstetric anatomical scans in an unselected population at a single tertiary centre and to characterise and stratify risk factors, genetic diagnosis and long-term health at 4 years old. Method: A single -centre cohort study of all major fetal CHDs detected on routine obstetric fetal anatomical ultrasound scans between January 2014 and December 2017 was performed in an unselected population. Demographic details, fetal echocardiogram reports, genetic test results, delivery outcomes and postnatal progress were stratified by CHD subtype. Results: Of 20,031 screened pregnancies, 109 pregnancies (0.53%) had major fetal CHDs. The most common subtypes were coarctation of aorta (17.4%), transposition of great arteries (16.5%), and tetralogy of Fallot and univentricular hearts (13.8% each). Of the 60.5% that underwent confirmatory genetic testing-mostly conventional karyotyping and testing for 22q11 microdeletion-about a quarter had abnormalities, of which 22q microdeletion was the most common. We had complete obstetric data in 85 pregnancies (78%), of which 76.5% progressed to live birth. Among these, 92.1% of postnatal echocardiograms concurred with antenatal ones. At 4 years old, 43.2% of offspring had no medical or developmental issues, 20.0% had mild medical or developmental issues, 21.5% had major medical or developmental issues, and 12.3% had deceased. Conclusion: Fetal echocardiograms accurately diagnose CHDs. Future studies should evaluate the roles of chromosomal microarray and next -generation sequencing in diagnosing CHD.