Causes of Bronchopulmonary Dysplasia
The exact cause of BPD is not known. The following conditions may increase your baby's risk of BPD:

Babies who are born premature or at a low birth weight are at increased risk of BPD. Most premature babies are born before vital organs have fully formed. They often have immature lungs that were damaged after birth. BPD often occurs in babies who weighed less than 2 pounds when they were born. The lower the birth weight and the more premature a baby is, the more likely he is to have BPD.

Other diseases or infections , such as respiratory distress syndrome (RDS) or pneumonia, increase your baby's risk for BPD. A heart problem that is present before birth may also increase your baby's risk.

Oxygen treatment that is given for a long time or in high amounts may damage lung tissues. The use of positive pressure or a mechanical ventilator for more than a month can increase your baby's risk of BPD.