Lung function deficits in preterm-born infants improved over time

Preterm-born survivors had decreased lung function, especially those with bronchopulmonary dysplasia, compared with term-born infants, but decreased values improved over time, according to research published in JAMA Pediatrics.

However, geographic region appeared to affect lung function in children with bronchopulmonary dysplasia.

“This comprehensive systematic review ... noted deficits in percentage predicted forced expiratory volume in 1 second for preterm-born participants when compared with term-born participants. Decrements were larger for the pre-term born participants who had bronchopulmonary dysplasia,” Sarah J. Kotecha, PhD, research associate in the department of child health at Cardiff University School of Medicine, U.K., and colleagues wrote. “Improvements in percentage predicted forced expiratory volume in 1 second were noted over time, especially for the bronchopulmonary dysplasia groups, possibly due to the introduction of surfactant and improvement in early-life therapies. Differences were also observed for percentage predicted forced expiratory volume in 1 second when geographical areas were compared with Scandinavian countries.”

For the systematic review and analysis, the researchers searched eight databases through December 2021 for studies that reported spirometry in preterm-born participants with or without a term-born control group. Eighty-six studies were identified and included. Researchers assessed associations between deficits in percent predicted FEV₁ and year of birth, age, introduction of surfactant therapy, and geographical region of birth and residence.

The primary outcome was deficit in percent predicted FEV₁ between preterm-born and term-born participants.

Researchers combined 50 studies with term-born controls with 36 studies that included 7,094 preterm-born and 17,700 term-born participants. Overall, there were 45 studies with preterm-born children without bronchopulmonary dysplasia; 29 studies reporting on bronchopulmonary dysplasia with supplemental oxygen dependency at 28 days; 26 studies reporting on bronchopulmonary dysplasia with supplemental oxygen dependency at 36 weeks’ postmenstrual age; and 86 studies with preterm-born participants.

Preterm-born infants had a mean deficit in FEV₁ percent predicted of –9.2% compared with term-born infants. Those without bronchopulmonary dysplasia had a deficit of –5.8% and those with bronchopulmonary dysplasia, regardless of supplemental oxygen dependency at 28 days or 36 weeks, had a deficit of –16%.

Researchers reported a significant narrowing of the difference in mean FEV₁ percent predicted as year of birth increased between preterm- and term-born participants, all preterm-born participants and all three bronchopulmonary dysplasia groups. However, there was no narrowing observed among the preterm-born participants without bronchopulmonary dysplasia.

Among all participants with bronchopulmonary dysplasia, those living in North America and western Europe had a deficit in FEV₁ percent predicted of –5.5% (P = .04) and –4.1% (P = .08), respectively, compared with those living in Scandinavia.

“These results emphasize the importance of being aware of the potential deficits when treating preterm-born survivors and of finding suitable treatments for the deficits observed in percent predicted FEV₁,” the researchers wrote.