The article presents the results of analysis of the preterm birth occurred at the Center for Family Planning and Reproduction of Health Department of Moscow in the period from 2008 to 2012. There were identified risk factors for the preterm birth, the diagnostic criteria for the preterm birth, there was worked out an algorithm of preterm labor with premature rupture of membranes depending on the period of gestation. The study showed that the preterm birth before 28 weeks of gestation was only 4.7 % of the total, but the survival rate of infants born before 26–27 weeks of gestation during a month was only 10 %. The leading reason for the death of infants with extremely low birth weight and very low birth weight are intraventricular hemorrhages grade III–IV. Cesarean section reduces perinatal mortality in preterm infants. Pregravid training is attributed to the preventive measures which could avoid the fact of premature termination of pregnancy. The last promotes normalization and improvement of uterine blood flow in 96.1 % of patients with the presence of modified Doppler indices in the «mother–placenta–fetus» system and developed preeclampsia and/or fetal growth retardation in the previous pregnancy. In this case reproductive losses in the patients included in the risk group are reduced by half.