It is not clear how asthma control before pregnancy impacts on pregnancy outcome. In contrast, there is evidence that adequate management during pregnancy decreases maternal and fetal morbidity. Asthma severity and suboptimal control are associated with adverse pregnancy outcomes. The effects of asthma on the fetus are still controversial and while systematic reviews report that FGR is more common in women with symptomatic asthma than in non-asthmatic women, the historic increased risk of preterm delivery is not borne out by prospective studies. Prolonged maternal hypoxia can lead to FGR and, ultimately, to fetal brain injury. An association between hypertension and asthma has also been suggested, and although there is an increase in gestational hypertension asthma does not seem to be a risk factor for pre-eclampsia.