Asthma and infertility are the most common disorders among women of reproductive age. Time to pregnancy is prolonged in women with asthma, and importantly, age seems to be a more important risk factor regarding fertility in women with asthma compared to women without asthma. Some data have shown a higher frequency of miscarriages in women with asthma, although the data are conflicting on this issue as studies have observed no association between asthma and pregnancy loss. Furthermore, studies have shown no negative effect of asthma on the total number of offspring. Pregnancy may, thus, have a significant impact on women with asthma, as well as on their offspring. The age of the women has an important impact on ability to conceive, but also for the pregnancy itself, with higher risk of uncontrolled asthma as well as asthma exacerbations with increasing age. Well-controlled asthma decreases the risk of maternal and fetal complications, while poorly controlled and undertreated asthma is associated with a range of risks for both mother and fetus. Asthma treatment should follow the general guidelines for asthma therapy, irrespective of pregnancy status, including treatment with inhaled corticosteroids, β2-agonists and muscarinic antagonists. Targeted treatment with biologics for severe asthma seems to be without important adverse effects. The use of systemic corticosteroids may be associated with adverse events during the first trimester; however, an exacerbation with the associated risk of hypoxaemia is worse for the fetus. Best possible asthma control may be achieved using repeated measurements of fractional exhaled nitric oxide (F ENO), as the use of F ENO compared with symptoms registration only has been shown to reduce exacerbation rate. In conclusion, women with asthma should be encouraged to conceive at an early age, might experience miscarriages, but the number of offspring are the same as in women without asthma. Well treated asthma is important for the well-being of both the mother and the unborn fetus.