Background Increasing evidence suggests that preterm birth affects later lung function. We systematically reviewed the literature to determine whether percentage predicted forced expiratory volume in 1 s (%FEV₁) is lower in later life in preterm-born subjects, with or without bronchopulmonary dysplasia (BPD), compared with term-born controls.

Methods Studies reporting %FEV₁, with or without a term-born control group, in later life for preterm-born subjects (<37 weeks gestation) were extracted from eight databases. Data were analysed using Review Manager and STATA. The quality of the studies was assessed.

Results From 8839 titles, 1124 full articles were screened and 59 were included: 28 studied preterm-born children without BPD, 24 with BPD₂₈ (supplemental oxygen dependency at 28 days), 15 with BPD₃₆ (supplemental oxygen dependency 36 weeks postmenstrual age) and 34 born preterm. For the preterm-born group without BPD and for the BPD₂₈ and BPD₃₆ groups the mean differences (and 95% CIs) for %FEV₁ compared with term-born controls were −7.2% (−8.7% to −5.6%), −16.2% (−19.9% to −12.4%) and −18.9% (−21.1% to −16.7%), respectively. Pooling all data on preterm-born subjects whether or not there was a control group gave a pooled %FEV₁ estimate of 91.0% (88.8% to 93.1%) for the preterm-born cohort without BPD, 83.7% (80.2% to 87.2%) for BPD₂₈ and 79.1% (76.9% to 81.3%) for BPD₃₆. Interestingly, %FEV₁ for BPD₂₈ has improved over the years.

Conclusions %FEV₁ is decreased in preterm-born survivors, even those who do not develop BPD. %FEV₁ of survivors of BPD₂₈ has improved over recent years. Long-term respiratory follow-up of preterm-born survivors is required as they may be at risk of developing chronic obstructive pulmonary disease.