Gestational age

<32 weeks

≥32 weeks

Time point of assessment

36 weeks PMA or discharge to home, whichever comes first.

>28 days but <56 days postnatal age or discharge to home, whichever comes first.

Treatment with oxygen > 21% for at least 28 days plus

Mild BPD

Breathing room air at 36 weeks PMA or discharge to home, whichever comes first.

Breathing room air by 56 days postnatal age or discharge to home, whichever comes first.

Moderate BPD

Need for <30% oxygen at 36 weeks PMA or discharge to home, whichever comes first.

Need for <30% oxygen at 56 days postnatal age or discharge to home, whichever comes first.

Severe BPD

Need for ≥30% oxygen and/or positive pressure (PPV or NCPAP) at 36 weeks PMA or discharge to home, whichever comes first.

Need for ≥30% oxygen and/or positive pressure (PPV or NCPAP) at 56 days postnatal age or discharge to home, whichever comes first.