Understanding Patent Ductus Arteriosus in Newborns

During fetal development, the majority of blood from the pulmonary artery flows into the descending aorta through the open ductus arteriosus. Once a baby is born and begins breathing, the oxygen levels in the blood increase, which triggers the ductus arteriosus to constrict. Additionally, the drop in pulmonary artery pressure and the decrease in blood flow through the ductus arteriosus contribute to its gradual closure.

What Happens If the Ductus Arteriosus Remains Open?

Normally, the ductus arteriosus closes shortly after birth. However, if it fails to close properly, the condition is known as patent ductus arteriosus (PDA). This congenital heart defect can lead to abnormal blood flow between the aorta and the pulmonary artery, which may cause various cardiovascular complications if left untreated.

Role of Vasoactive Substances

The constriction or dilation of the ductus arteriosus is also influenced by vasoactive substances, particularly prostaglandins. These biochemical compounds play a key role in maintaining the patency of the ductus during fetal life and may delay its closure after birth if their levels remain high.

Types of Patent Ductus Arteriosus

Patent ductus arteriosus can be classified into three main types based on its anatomical shape: funnel-shaped, tubular, and window-type. Each type may vary in size and impact on blood flow, which can influence the severity of symptoms and the approach to treatment.

Gender Prevalence

This condition is more commonly diagnosed in females than in males, with a female-to-male ratio of approximately 2–3:1. The reason for this gender disparity is not entirely clear, but it suggests a possible hormonal or genetic influence.