In the UFO there are different models of perinatal care (MVPN, MNPN, M), which introduced a system of monitoring of cases of maternal mortality. The study of the dependence of the frequency of critical obstetric conditions on the model of perinatal care in the UFO was not revealed, but most clearly shows its advantage of a three-level system of perinatal care in the territory of the Yamal-Nenets Autonomous district by reducing the proportion of critical obstetric conditions (from 0.8% to 0.3%) after the completion of the three-level system of perinatal care. With regard to the models of perinatal care organization, the predominance of NM share in the model of MVPN was revealed. In addition, the MVPN model was dominated by all causes of critical obstetric conditions. In this case, bleeding is the leader of the causes at any gestation period. NM monitoring allowed to assess the optimality of the organization of a three-level system of perinatal care for the prevention of critical obstetric conditions.