Analysis of the epidemiological and demographic characteristics of HIV-infected pregnant women is important for organizing effective care for this group of patients and further reducing the frequency of mother-to-child transmission. Between 2014 and 2017 in Saint-Petersburg, there were 2524 deliveries in HIV-infected women who were observed during pregnancy, mainly in the Saint-Petersburg AIDS Center (AIDS Center). The average frequency of perinatal HIV transmission over the study period in the city was 1,3%, which is lower than the average for Russia. Out of 2524 women recently confined, 1858 HIV-infected women, who were observed during pregnancy at the AIDS Center in 2014–2017, were enrolled. Risk groups for perinatal HIV transmission in Saint-Petersburg are HIV-infected pregnant women: external or internal migrants, women with late registration at the dispensary registration for pregnancy in the antenatal clinic and the AIDS Center and, accordingly, late initiation of perinatal HIV transmission, active consumers of surfactants, pregnant women with low adherence to observation in medical institutions and to getting antiretroviral agents. The increase in coverage of the city’s population with HIV testing reveals new infections, including among women of reproductive age, as well as their partners. The timely use of ARV at the planning stage of pregnancy reduces perinatal HIV transmission and the risks of opportunistic diseases. The availability of medical care and free distribution of ARV drugs to all pregnant women who applied to the AIDS Center helps to reduce perinatal HIV transmission, including among internal and external migrants who do not have a permanent registration in Saint-Petersburg. Counseling women at the planning stage and during pregnancy by various specialists of the AIDS Center (gynecologists, infectious disease specialists, psychologists, narcologists) allows one to form a commitment to monitoring, to receiving ARV, giving up bad habits, to reduce the incidence of HIV-dissidence.