What is bronchopulmonary dysplasia (BPD)?
Bronchopulmonary dysplasia (BPD) is a chronic lung disease that affects infants. BPD is usually seen in premature babies who were born early with underdeveloped lungs and received mechanical ventilation and oxygen after birth. Babies with BPD have chronic respiratory failure, need oxygen and have abnormal chest x-rays.
BPD often results in long-term breathing problems such as asthma, exercise limitations, a need for supplemental oxygen and more severe stress on the heart and lungs. Although some infants recover from BPD, others have long-term health problems as a result and many require intensive medical care.
Along with asthma and cystic fibrosis, bronchopulmonary dysplasia is one of the most common chronic lung diseases in children. According to the National Heart, Lung, and Blood Institute (NHLBI), between 5,000 and 10,000 cases of BPD occur every year in the United States.
What causes bronchopulmonary dysplasia?
Children are not born with BPD. The condition develops as a result of premature birth and progressive lung injury after birth, caused when babies need help breathing.
Most BPD cases occur in premature infants, usually born at 34 weeks' gestation or before, who weigh less than 4.5 pounds. These babies are more likely to be affected by infant respiratory distress syndrome (RDS), also called hyaline membrane disease, at birth.
The lungs of babies with RDS are too immature to allow them to breathe on their own, so mechanical ventilators breathe for them. Although the ventilator is life-saving, it can contribute to long-term breathing problems.
Over time, pressure from the ventilator and increased oxygen intake can injure a newborn's delicate lungs. Almost half of all extremely low birth weight infants will develop some form of lung injury. If symptoms persist at 36 weeks post-conception, a diagnosis of BPD is made. As babies mature, they grow more lung tissue, which can improve their breathing.
BPD also can develop from other injuries to a newborn's fragile lungs such as trauma, pneumonia and other infections. All of these can contribute to the inflammation and scarring associated with BPD, even in a full-term newborn.
Who gets bronchopulmonary dysplasia?
Bronchopulmonary dysplasia (BPD) occurs in different infants for different reasons. It can happen in full-term as well as premature infants, and doctors believe that it's due to an individual infant's response to a number of possible factors. The more premature a baby is at birth, the greater the chance of developing BPD.
Children with extremely low birth weight (less than 2.2 pounds) are most at risk for developing BPD. Among babies who are premature and have a low birth weight, white male infants seem to have the greatest risk of developing BPD, for unknown reasons. Genetics may contribute to some cases of BPD as well.