Abstract
In order to study the prevalence of asthma in women of childbearing age in 2014-2016 in St. Petersburg, a questionnaire of pregnant women at the stage of registration in a women's consultation was conducted. The official diagnosis of asthma was 4.83% of respondents, according to the results of the questionnaire, 14.64% of women of childbearing age report symptoms of bronchial asthma. The study results among pregnants with antepregnant diagnosis of asthma as well within women who marked the presence of asthma symptoms in questionaries' while pregnancy, show, that the forced expiration volume can remain within normal values even in patients with moderate bronchial asthma. The earliest indicators of the spirography and pletizmograph y are the maximum volume speed at an exhalation of 50% of FVC, the level of the bronchial resistance (Raw) and bronchial passability (SGaw). Correlations of these changes with existence of bronchial obstruction signs was shown. Mostly marked correlarion was discovered between severity of asthma duration and the base level of the maximum volume speed at an exhalation of 50% of FVC, as well as the increase of this value during the test with beta2agonist. There are reliable differences in values of the spirography and the pletizmography in groups with presence and absence of signs of bronchial obstruction.