Maternal smoking and respiratory distress syndrome

Infants of 603 patients on whom information about smoking habits during pregnancy was available were studied for incidence respiratory distress syndrome. Among the 360 patients who did not smoke, the incidence of respiratory distress syndrome in the neonate was 15.1%, whereas among patients who smoked, the incidence was 9.1%. We speculate that smoking produces a condition of chronic stress in the fetus which brings about an acceleration of fetal pulmonary maturation.