What does it detect ?

It shows the heart's structure, function, rhythm, and blood vessels, as well as any problems with the heart walls and valves in detail.

When this test should be done?

A fetal echo is usually performed during the second trimester, when the mother is around 18 to 24 weeks pregnant. The optimal time for a screening echo is 22 to 26 weeks, but sometimes a repeat exam is necessary.

Is this test painful or need any special preparation?

The test is painless and takes about 30 to 45 minutes. It's performed on an outpatient basis in a darkened room while the mother is lying down. No it doesn't need any special preparation. Mother can eat, drink or even empty her bladder before the test.