The purpose of this study was to identify the relationship between the microbiological status of women and newborns, and the development of premature labor. Materials and Methods: The study included 227 pregnant women at gestational age between 28 and 36 weeks and 6 days. All women underwent an assessment of vaginal microcenosis and the quantitative and qualitative composition of the biotope of the cervical discharge; the newborns underwent bacteriological examination of the auricle, pharynx and anus. Results: Disturbances in the vaginal biotope were diagnosed in every second woman. We found that the shorter the gestation period, the higher the frequency of disturbances in the vaginal biotope, and the risk of premature birth at an earlier time correlates with the presence of infection in the mother. The risk of giving birth to an infected child is 4.2 times higher at birth from a mother who has disturbances in the biotope, compared to a woman with a normal biotope.