Mainstream technology can be used only in the presence of an endotracheal tube, but copes better with rapid respiratory rates and very small tidal volumes.

Among men (who already have a heightened risk of chronic respiratory disease due to their higher rates of smoking), exposure to indoor smoke nearly doubles that risk.

With every week of gestation after 34 weeks, however, Hibbard found that rates of complications dropped - by 40 weeks, only 0.3% of babies showed signs of respiratory distress.