Since the first report by Simpson (1957) of the association between premature birth and maternal smoking, the research on the consequences of maternal smoking during pregnancy on perinatal outcome has been intense. Even if some of the findings have been contradictory, it is now evident that maternal smoking is associated with pre-term birth and low birth weight, low birth weight for gestational age, small head circumference, low Apgar score at 5 min, stillbirth and neonatal death.