Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Blue baby
Medically reviewed by Min Clinic Staff | Updated: January 2026
Blue baby: A baby who is cyanotic (blue), due usually to a heart malformation that prevents the baby's blood from being fully oxygenated. The bluish color reflects the deoxygenated state of the blood. (Oxygenated blood is red.) Sometimes the term "blue baby" is also applied to a child who is cyanotic due to failure by the lungs to oxygenate the blood.
