Effect of antenatal corticosteroid treatment on lung function in full-term newborn infants

Antenatal treatment of pregnant women with corticosteroids in order to stimulate surfactant production has been shown to be effective. However, lung structure is also affected by the treatment.

We tested the hypothesis that changes within lung acini, induced by maternal corticosteroid treatment, persist during lung development.

Twenty-two healthy infants, whose mothers were treated with up to three doses of betamethasone at 25-33 weeks of pregnancy because of preterm labour, but where labour terminated and the infants were born at term, were studied at term and compared to a group of 50 healthy newborn infants without prenatal treatment with corticosteroids. Gas-mixing efficiency was measured in terms of moment ratio with a nitrogen washout method together with functional residual capacity. Mechanical parameters were assessed with the single occlusion technique.

There were no signs of disturbed gas mixing or changed lung volume or mechanics in the treated group.

The result contributes to an emerging body of evidence that antenatal treatment with corticosteroids does not permanently affect lung structure or function.