Extracardiac malformations (ECMs) and chromosomal abnormalities are
common in fetuses with some congenital heart defects (CHD). The frequency and type
of ECMs and chromosomal abnormalities vary according to the type of CHD and the
studied population. The detection rate of CHD and ECMs depends on the first-trimester
screening through nuchal translucence (NT) measurement, second trimester anomaly
scan, and fetal echocardiography. The CHDs most frequently associated with ECMs
are atrioventricular septal defect (AVSD), ventricular septal defect (VSD), tetralogy of
Fallot (TOF), hypoplastic left heart syndrome (HLHS), tricuspid atresia (TA), aortic
arch, coarctation of the aorta (CoA) and interruption of the aortic arch (IAA).
Conversely, the association of ECMs and chromosomal abnormalities with the
transposition of the great arteries (TGA) is low. CHD such as: Ebstein's anomaly, left
ventricular outflow tract obstruction (aortic stenosis) and obstruction of the right
ventricular outflow tract (atresia and pulmonary stenosis) are associated with extremely
low ECMs and chromosomal abnormalities, and are limited to a few sporadic cases.
Keywords: Chromosomal abnormalities, Congenital heart defects, Genetic
syndromes, Non-cardiac anomalies.
