The earlier a baby is born before his or her due date and the lower his or her weight at birth, the greater the risk of bronchopulmonary dysplasia (BPD).
Most babies who are diagnosed with BPD weigh less than 2 pounds (about 1,000 grams) at birth. About 1 of every 3 newborns who weighs less than 2 pounds at birth gets BPD.
The number of babies who develop BPD is higher than it was 30 years ago. This is because of advances in care that help more premature infants survive.
Many babies who develop BPD are born with serious respiratory distress syndrome (RDS). However, some babies who have mild RDS or don't have RDS also can develop BPD. These babies often have very low birth weights and another condition, such as patent ductus arteriosus (PDA) or sepsis.
PDA is a heart problem that occurs soon after birth in some babies. Sepsis is a serious bacterial infection in the bloodstream.