Learn About Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a form of chronic lung disease that can affect newborns, most often those who are born very early or before 32 weeks of gestation (8 or more weeks before the anticipated due date). When babies are born this early, their vital organs, including their lungs, aren’t fully developed.

This can lead to potential short and longer-term health problems. When the lungs are underdeveloped, your baby may need more support to breathe effectively. These types of breathing support may include:

• supplemental oxygen,
• supplemental airway pressure using CPAP (continuous positive airway pressure – typically delivered via short prongs or mask around the nose),
• or a mechanical ventilation (a machine that helps them breathe using a breathing tube placed in trachea or windpipe).

While these forms of breathing support can help save your baby’s life, in some infants, they may cause injury to their underdeveloped lungs that can be difficult to avoid. BPD develops over the first weeks and months after preterm birth, when the lungs and the airways (bronchi) are injured. This causes tissue destruction, scarring, or abnormal growth (dysplasia) of the tiny air sacs in the lungs (alveoli).

Key Facts

• Babies are not born with BPD; it develops during the first weeks and months after birth. BPD is more common in infants diagnosed with respiratory distress syndrome (RDS) in the first hours and days after birth. RDS is caused by absence or low production of surfactant in the lungs (a soapy-like substance that helps the lungs fill and empty of air during breathing).  
• An estimated 10,000 to 15,000 newborns develop BPD in the United States every year.
• The severity of the disease varies from infant to infant. The more premature the newborn, the greater the risk of developing BPD.

How Bronchopulmonary Dysplasia Affects Your Body

In the lungs, BPD results from injury to the developing alveoli and airways, as well as abnormal healing and repair after injury occurs. The lower the number of working alveoli, the longer infants may need to remain on a ventilator or supplemental oxygen to support their breathing. In some infants, prolonged use of this often life-saving support can cause further damage to the child’s lungs.

In addition to underdevelopment of the lungs and injury that occurs after birth, the tiny blood vessels that surround the alveoli and bring blood in and out of the lungs may also be affected. This can make passage of blood through the lungs more difficult. Long term, the increased pressure inside these blood vessels can cause pulmonary hypertension (high blood pressure within the small arteries in the lungs. Pulmonary hypertension can make it more difficult for the heart to pump blood to the lungs). Infants who develop pulmonary hypertension, in addition to BPD, may require extra medications to support their heart function. In severe cases, heart failure may occur.

Newborns who suffer from BPD may also experience difficulty with feeding and growth as well as later development of motor and language skills. These challenges can be more significant in infants who develop greater severity of lung disease.

What Causes Bronchopulmonary Dysplasia?

BPD is a respiratory disease that can occur when a newborn’s lungs are undeveloped at birth and support with a ventilator or supplemental oxygen is required to ensure adequate breathing. Because newborns’ lungs are delicate and vulnerable, high amounts of inhaled oxygen and pressure may overstretch the lungs and cause inflammation and damage to the inside lining of the airways, the alveoli, and the blood vessels around them. The risk of injury increases with greater prematurity (i.e., infants born further before their expected due date are more likely to develop BPD). As such, BPD is primarily a complication of prematurity and is uncommon among infants born after 32 weeks of gestation.

During pregnancy, different conditions may affect the growth of the fetus and may also lead to premature labor. Prenatal infection including chorioamnionitis, complications of pregnancy such as preeclampsia, as some avoidable exposures such as maternal smoking and illicit drug use may contribute to lung underdevelopment and likelihood of preterm delivery. These in turn increase an infant’s risk of developing BPD.

After birth, preterm infants may experience early breathing problems in the form of respiratory distress syndrome (RDS). The presence of RDS is closely linked to the development of BPD, although only some infants with RDS develop BPD. Another condition called patent ductus arteriosus (PDA), a heart defect in which a normal fetal blood vessel connecting the right and left side of the heart fails to close and remains open after birth, is another risk factor associated with the development of BPD.

Who Is at Risk for BPD?

The degree of prematurity, and therefore degree of lung immaturity or underdevelopment at birth, is largely what puts a child at risk of developing BPD. Most newborns who develop BPD are born more than 10 weeks early, weigh less than two pounds at birth, and experience breathing problems within the first few hours or days after birth. BPD is rare in infants born after 32 weeks of pregnancy.