Objectives: To determine whether respiratory allergy or hyperreactive nasal mucosa is exceptionally common in women with pregnancy rhinitis, and to evaluate other possible risk factors such as clinical asthma or rhinitis, smoking, age, parity, and sex of the child. Patients and Methods: From an antenatal questionnaire study, 165 women, 83 (50%) of whom had had pregnancy rhinitis, were examined 6 months after delivery, and multiple antigen simulataneous testing chemiluminescent assay (MAST CLA) (10 airborne allergens) was performed. After histamine provocations, rhinostereometry and acoustic rhinometry were performed in 25 of them. Serum levels of soluble intercellular adhesion molecule-1 were determined 4 times during and once after pregnancy in 5 women with pregnancy rhinitis and 17 without pregnancy rhinitis. Results: Thirty-nine women (24%) were sensitized to 1 or more allergen. The pregnancy rhinitis group showed significantly higher levels of IgE to house dust mites. There were also more smokers in the pregnancy rhinitis group. Clinical asthma or rhinitis, age, parity, and sex of the child did not differ significantly between the 2 groups. Mucosal swelling increased with rising concentrations of histamine, as measured with rhinostereometry, but there was no significant difference between the 2 groups in any of the variables. Serum soluble intercellular adhesion molecule-1 was not elevated in the pregnancy rhinitis group. Conclusions: This study found no increased frequency of allergy in general in women who have had pregnancy rhinitis. However, IgE against house dust mite was more frequent in the pregnancy rhinitis group. Smoking seems to be a risk factor, but age, parity, sex of the child, and hyperreactive nasal mucosa do not. Soluble intercellular adhesion molecule-1 was not elevated during pregnancy rhinitis.