Adult and fetal. A fetal "echo" means a fetal echocardiogram. This is a detailed ultrasound of the fetus' heart, and it is done through the mother's abdomen. An adult can have an echocardiogram as well. It is either done through the chest wall, or with a special transducer that goes down the adult's esophagus ("transesophageal") to get closer pictures of the person's heart.