How long does it take for an ASD to close?

How Long Does It Take for an Atrial Septal Defect to Close?

An atrial septal defect (ASD) is a small hole in the wall that separates the two upper chambers of the heart — the atria. It's actually normal for babies to be born with this opening; it’s part of fetal circulation, allowing blood to bypass the lungs before birth. In most cases, this hole closes on its own within the first few weeks or months of life, often without causing any noticeable issues.

When the opening remains beyond infancy, it’s still referred to as an ASD. Many small ASDs may close spontaneously by age 2, especially if they’re not causing symptoms or affecting heart function. Doctors often take a “watchful waiting” approach, monitoring the child with regular check-ups and echocardiograms to see how the heart is developing.

While some defects close within months, others may persist into childhood or even adulthood. In those cases, intervention might be needed — but many people live with small ASDs their entire lives without ever knowing, especially if the hole is tiny and doesn’t strain the heart.

The good news is that when treatment is necessary, options like catheter-based closure or surgery are highly effective. Advances in cardiology mean most children with ASDs grow up to lead completely normal, healthy lives. If you or your child has been diagnosed with an ASD, rest assured: with proper follow-up, the outlook is often excellent.