Summary: Asthma and allergic diseases are the most common chronic diseases in pregnant women. During pregnancy asthma may be exacerbated, ameliorated or may be similar as before. Untreated, uncontrolled asthma brings with it a number of risks for the mother and the fetus, such as suppression of intrauterine fetal growth, preterm delivery, more frequent treatment by cesarean section, low birth weight of the newborn or increased perinatal mortality. The diagnostics does not differ from that carried out in the general population, but skin tests and provocative tests are avoided. Disease monitoring is based on the control of the mother’s clinical condition, but also on fetal well-being. Proper control of the disease, regular taking of medicines and prevention of allergic diseases allow for the proper development of the pregnancy and fetus and reduce the risk of complications to a minimum. Most drugs used for the treatment of asthma and allergies can be used during pregnancy, because greater risk is associated with a worsening of the chronic maternal disease than the pharmacological agents used. The most dangerous event is the occurrence of a severe exacerbation and anaphylactic reaction in pregnancy, which requires rapid and intensive therapeutic treatment. The effective and safe handling of allergic diseases, in particular asthma, requires constant cooperation of the obstetrician and allergologist, but also cooperation and education of the mother.