A chronic lung disorder associated with pulmonary maldevelopment, scarring, and/or inflammation that develops in preterm neonates exposed to supplemental oxygen for at least 28 days. For infants born before 32 weeks gestation with moderate BPD, there is a supplemental oxygen requirement of less than 30% at 36 weeks postmenstrual age or earlier discharge. For infants born after 32 weeks with moderate BPD, there is a supplemental oxygen requirement of less than 30% at 56 days post-natal age or at earlier discharge. [from
NCI]