Fetal echocardiography.

In recent years, fetal echocardiography has greatly improved in that most major structural heart defects are detectable from 18 weeks on. Fetal M-mode mapping has also enabled us to detect and diagnose fetal arrhythmias as well as follow their treatment. More recently, pulsed Doppler and color-flow mapping have facilitated the dynamic study of blood flow in the cardiovascular system. Fetal echocardiography has now become a sophisticated modality, but is a crucial one to master because most fetuses that have congenital heart defects are not necessarily at any high risk. Evaluation of the fetal heart, therefore, is a recommended part of the routine fetal structural survey.