PHi everyone. I have read articles on the definition (old and new) of BPD but I am still unclear in certain aspects. A 26 week old preterm infant needed supplemental oxygen for more than 28 days  but was successfully weaned of this before 36week postmenstrual age; does this baby meet criteria for BPD? Or is it mandatory for the 36 PMA criteria to be met before considering BPD at all? Thank you

For preterm infants born before 32 weeks postmenstrual age the point of assessment is at 36 weeks postmenstrual age (or at discharge, whichever comes first). For preterm infants born ≥ 32 weeks postmenstral age you assess at >28 days (but <56 days postnatal age or at discharge home, whichever comes first).

Then you have to consider the treatment with oxygen >21% for at least 28 d plus

• for mild BPD: Breathing room air at 36 weeks postmenstrual age/by >28days (<56 days) age or at discharge, whichever comes first
• for moderate BPD: Need for<30% at 36 weeks postmenstrual age/by >28days (<56 days) age or at discharge, whichever comes first
• for severe BPD: Need for ≥30% oxygen and/or positive pressure(PPV or NCPAP) at 36 weeks postmenstrual/by >28days (<56 days) age or at discharge, whichever comes first

So the preemie you talk about would have a mild BPD by the NIH workshop definition.

I hope this helped you.