Impact of ethnicity and extreme prematurity on infant pulmonary function

Summary The impact of birth before 27 completed weeks of gestation on infant pulmonary function (PF) was explored in a multi‐ethnic population in comparison to more mature preterm controls (PTC) and healthy fullterm infants. Plethysmographic lung volume (FRC pleth ) and forced expired volume (FEV 0.5 ) were obtained at ∼12 months post‐term age in 52 extremely preterm (EP) infants (median [range] gestational age [GA]: 26 [23–27] weeks; 40% White mothers; 79% with BPD), 41 PTC (GA:35 [30–36] weeks; 37% White mothers) and 95 fullterm infants (GA:40 [37–42] weeks; 86% White mothers). Using reference equations based on identical equipment and techniques, results were expressed as z ‐scores to adjust for age, sex and body size. FEV 0.5 was significantly lower in EP infants when compared with PTC (mean difference [95% CI]: −1.02[−1.60; −0.44] z ‐scores, P  < 0.001), as was forced vital capacity (FVC) but there were no significant differences in FRC pleth or FEV 0.5 /FVC ratio. FEV 0.5 , FVC, and FEV 0.5 /FVC were significantly lower in both preterm groups when compared with fullterm controls. On multivariable analyses of the combined preterm dataset: FEV 0.5 at ∼1 year was 0.11 [0.05; 0.17] z ‐scores higher/week GA, and 1.28 (0.49; 2.08) z ‐scores lower in EP infants with prior BPD. Among non‐white preterm infants, FEV 0.5 was 0.70 (0.17; 1.24) z ‐scores lower, with similar reductions in FVC, such that there were no ethnic differences in FEV 0.5 /FVC. Similar ethnic differences were observed among fullterm infants. These results confirm the negative impact of preterm birth on subsequent lung development, especially following a diagnosis of BPD, and emphasize the importance of taking ethnic background into account when interpreting results during infancy as in older subjects. Pediatr Pulmonol. 2014; 49:679–687. © 2013 Wiley Periodicals, Inc.