Question: When is the ideal time to perform a fetal echocardiogram? Magdalena (Salamanca).
Answer: At week 12, the fetal heart is fully formed, like that of a miniature adult. Its size is 8 mm. with which the diagnosis is practically impossible. Between week 12-17 it doubles in size and in week 21 it triples. Hence, the ideal time to perform a fetal echocardiography is between weeks 17 and 21.