The purpose of the study was the determination of diagnostic and prognostic value of a comprehensive research of interferon status in pregnant women with high infectious risk. 100 patients were investigated: 65 pregnant women with urogenital infections (UGI), 20 patients without UGI, who had labour in time and 15 non-pregnant women. The determining of interferon status and cellular sensitivity to interferon preparations was conducted by a biological method. It was found that in pregnant women with preterm birth (PB) in the context of high levels of IFN-γ gene its production in the culture of leukocytes was reduced, which indicates a violation of the production of IFN-γ at the posttranscriptional level. The ratio of induced production by peripheral blood leukocytes IFN-α and IFN-γ as 5 and more allows predicting the preterm birth with high accuracy (positive predictive value — 69 %, negative predictive value — 85.7 %, sensitivity — 90 %, specificity — 60 %).