Atrial Septal Defect in Infants: When Does It Require Medical Intervention?

An atrial septal defect (ASD) in infants measuring more than 5mm is less likely to close on its own as the child grows. However, spontaneous closure is not entirely impossible. It is crucial for parents to follow up regularly with a pediatric cardiologist to monitor any changes in the size of the defect. Many small ASDs can be observed until the child reaches 1 to 2 years of age.

Understanding the Natural Progression of ASD

Some infants may experience a reduction in the size of the ASD as they grow. For example, a defect initially measured at 7-8mm might decrease to around 2-3mm by the age of 2. While this is considered an improvement, it does not always equate to full closure. In such cases, continued monitoring is recommended to assess whether further intervention becomes necessary.

When Surgical or Interventional Treatment Is Advised

If the defect remains larger than 5mm after the age of 2, or if it shows no signs of shrinking—or worse, begins to increase in size—doctors may recommend a minimally invasive cardiac procedure. This typically involves the placement of a septal occluder device through a catheter-based approach, which effectively seals the hole in the heart.

Why Early Intervention Matters

Timely treatment of a persistent atrial septal defect can help prevent long-term complications such as reduced heart function or the risk of developing infective endocarditis. Early intervention significantly improves long-term outcomes and supports healthy cardiovascular development in children.