Spontaneous heart disease in newborns refers to unexpected cardiac conditions present at or shortly after birth, often without prior family history. Causes may include congenital heart defects (CHDs), maternal infections during pregnancy, genetic mutations, or environmental exposures. These abnormalities can affect heart structure or function, leading to symptoms like cyanosis, rapid breathing, or poor feeding. Early diagnosis is crucial and typically involves physical examination, pulse oximetry, echocardiography, and sometimes genetic testing. Prompt detection allows timely intervention, improving outcomes. Understanding underlying causes is essential for guiding treatment and counseling families, especially in cases with potential genetic links or recurrence risks.