ABSTRACT
Two-dimensional (2D) ultrasound imaging of the fetal heart has been steadily evolving since its original descriptions in the early 1980s. Cardiac defects in fetuses are one of the most frequently missed findings on prenatal ultrasound evaluation with significant complex consequences. Early fetal echocardiography with the use of high-resolution transvaginal ultrasound between 13 and 16 weeks of gestation has provided the capability to demonstrate all cardiac structures and the majority of major CHDs. Fetal echocardiography is commonly performed between 18 and 22 weeks of gestational age. The heart should fill about one-third of the thoracic area or about half the thoracic circumference. Significant levorotation of the cardiac axis is often the first clue to the presence of a congenital heart defect. Ventricular hypoplasia or dilation is easily appreciated in the four-chamber view.
