Objectives To report the current incidence of bronchopulmonary dysplasia (BPD) and to compare changes in weight and head circumference between infants who developed BPD and infants who did not.

Design Retrospective, whole-population study.

Setting All neonatal units in England between 2014 and 2018.

Patients All liveborn infants born <28 completed weeks of gestation.

Interventions The change in weight z-score (ΔWz) was calculated by subtracting the birthweight z-score from the weight z-score at 36 weeks postmenstrual age (PMA) and at discharge. The change in head circumference z-score (ΔHz) was calculated by subtracting the birth head circumference z-score from the head circumference z-score at discharge.

Main outcome measure BPD was defined as the need for any respiratory support at 36 weeks PMA.

Results 11 806 infants were included in the analysis. The incidence of BPD was 57.5%, and 18.9% of the infants died before 36 weeks PMA. The median (IQR) ΔWz from birth to 36 weeks PMA was significantly smaller in infants who developed BPD (−0.69 (−1.28 to −0.14), n=6105) than in those who did not develop BPD (−0.89 (−1.40 to −0.33), n=2390; adjusted p<0.001). The median (IQR) ΔHz from birth to discharge was significantly smaller in infants who developed BPD (−0.33 (−1.69 to 0.71)) than in those who did not develop BPD (−0.61 (−1.85 to 0.35); adjusted p<0.001).

Conclusions Postnatal growth was better in infants diagnosed with BPD compared with infants without BPD possibly due to more aggressive nutrition strategies.