ABSTRACT
Background Coarctation (from the Latin for “constriction”) refers to a narrowing of the aorta, usually at the isthmus, and usually with a discrete “posterior shelf” of tissue causing the narrowing of the isthmic lumen. This is one of the more common forms of congenital heart disease, constituting 5% of cases, with an incidence of 3-5 cases per 10,000 live births.1-4 Despite coarctation being relatively common, it is considered one of the more difficult lesions to diagnose in the fetus,5 with approximately a third of cases diagnosed prenatally.6,7 As discussed in this chapter, this low rate of detection is probably due to the unique nature of fetal circulation, the physiologic and anatomic changes that occur in the perinatal period, and, in particular, the relationship between the ductus arteriosus and the aortic isthmus.
