When does PDA normally close?

When Does the Ductus Arteriosus Close After Birth?

The ductus arteriosus is a vital blood vessel in fetal development, connecting the pulmonary artery to the aorta. This small but crucial passage allows oxygen-rich blood from the mother to bypass the unborn baby’s non-functioning lungs and circulate efficiently through the body. Normally, this vessel begins to close within the first few hours to days after birth, once the baby starts breathing independently and the lungs take over oxygen exchange.

In most newborns, the closure process is well underway by 10 to 15 hours after delivery, with complete closure typically occurring within the first few days of life. The drop in pulmonary pressure and the change in oxygen levels after the first breath trigger this natural physiological response. By 24 to 48 hours, the ductus arteriosus should be functionally closed in healthy infants, eventually turning into a fibrous ligament known as the ligamentum arteriosum.

However, in some cases—particularly among premature babies—the vessel remains open, a condition known as patent ductus arteriosus (PDA). When this happens, blood can continue to flow abnormally between the aorta and pulmonary artery, potentially leading to heart strain and breathing difficulties. While full-term infants with PDA are less common, they still require medical evaluation. Treatment may include medications or, in more persistent cases, minimally invasive procedures to close the vessel.

Understanding the normal timeline of ductus arteriosus closure helps doctors identify infants who may need early intervention. For the vast majority of babies, though, this transition happens smoothly, marking one of the first quiet miracles of newborn life.