Fetal echocardiography is not recommended in all pregnancies, however is needed in the following cases:

• There is an increased risk of any heart disorder or abnormality
• There is a family history of heart diseases or ailments
• The Mother is under medications that cause heart related problems e.g epilepsy etc.
• The mother has a previous child with chronic heart disease
• There is a risk of Autoimmune diseases
• In cases of infections: Parvovirus, Rubella, Coxsackie etc.
• There is alcohol or drug abuse during pregnancy
• The mother has diabetes / phenylketonuria / lupus etc.
• There is Twin Pregnancy with the common Placenta

• Two-dimensional Echocardiography: It is used to see the actual real time motion of the heart & related structures which helps doctors to evaluate the heart & its functioning. It appears cone-shaped.
• Four-dimensional) Ultrasonograph: It uses a special probe which acquires a series of images of the beating fetal heart that can be seen in multiple planes at the same time. The images can be reconstructed to provide a more realistic view to better understand and diagnose the disease or abnormality that can affect the fetal heart.
• Doppler Echocardiography: It is used to detect the abnormal blood flow through heart chambers and valves by assessing and measuring the blood flow through them. It helps to indicate the problems/defects associated with the heart valves, heart's wall and its chambers.
• Color Doppler: Similar to Doppler ECHO, it simplifies its findings with different colors to indicate the direction of blood flow.

Depending upon the findings in the diagnosis, if any defects are detected then your doctor may ask you to have some other tests such as MRI, Amniocentesis, Biophysical profile, Genetic counselling etc.

Findings from these tests can help you and your doctor to plan the treatment and correctional surgeries if required after birth.
Not all the anomalies can be detected, some such as a hole in the heart is difficult to see even with these advanced tests. your doctor will explain to you what these tests  can or cannot diagnose.