Influence of gender on lung function outcomes at eleven to fourteen years of age in children born very prematurely

Abstract

Background:

Follow-up in infancy of children born very prematurely ( below 29 weeks of gestational age) entered into the United Kingdom Oscillation Study (UKOS) demonstrated significantly more short and longer term (up to two years of age) respiratory morbidity in males versus females.

Aim:

To test the hypothesis that lung function at 11-14 years of age in children born very prematurely would be worse in males compared to females.

Methods:

Lung function was assessed in 248 children at 11-14 years of age who were entered into the UKOS study. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1:FVC, residual volume (RV), transfer factor for carbon monoxide (TLCO), and functional residual capacity by plethysmography (FRCpleth) and helium gas dilution (FRCHe) were assessed. Results were considered abnormal if z score less then -2, except RV results which were considered abnormal if z score greater then 2.

Results

One hundred and twenty of the children assessed were female and 127 male. A significantly higher proportion of the male children were oxygen dependant at 28 days after birth (85% versus 75%, p=0.037) and at discharge (30% versus 12%, p=0.001). A higher proportion of the males had a abnormal FEV1 (19% versus 4%, p=0.001), an abnormal FEV1:FVC (39% versus 29%, p=0.055) and an abnormal RV (13% versus 3% female, p=0.001). A greater proportion of the females, however had an abnormal TLCO (20% versus 8%, p=0.01).

Conclusion

Male compared to female children born extremely prematurely have greater airways obstruction at follow-up, which may reflect they are more prone to develop bronchopulmonary dysplasia.