RESEARCH OBJECTIVES: Compare rhinomanometry results of pregnant women in their first trimester, pregnant women in their second or third trimester and non-pregnant women. Examine the correlation between estrogen-induced rhinopathy in pregnant women with smoking, chronic respiratory diseases (CRDs), allergic rhinitis, and body mass index (BMI). STUDY DESIGN: Cross-sectional study. SUBJECTS AND METHODS: The study examined a sample of 63 women divided into four study groups.The first group comprised women in their first trimester of pregnancy; the second group comprised women in their second or third trimester; the third group comprised non -pregnant women in the follicular phase of their menstrual cycle; and the fourth group comprised non - pregnant women in the luteal phase of their menstrual cycle.. Exclusion factors for all four study groups included a presence of mechanical obstruction in nasal breathing, a presence of acute allergy symptomsat the time of research, and receiving of exogenous female sex hormone therapy. The main research methods used included a questionnaire (comprised of 21 questions) and computerized rhinomanometry. RESULTS: No difference was observed in nasal airway resistance between the four study groups. No difference was observed in nasal airway resistance between the group of pregnant women who smoke and the group of pregnant women who do not smoke, as well as between the group of pregnant women who are overweight and the group of pregnant women who are of normal body mass. No difference was observed between the group of women who suffer from allergic rhinitis during the year and the group of women who do not. Pregnant women suffering from CRDs were found to have highernasal airway resistanceduring expiration than the group of women not suffering from CRDs. CONCLUSION: The non-existence of a significant statistical difference between the observed groups is ascribed to the limited size of the sample.