Background: In the Brazilian Public healthcare system (The Unified Healthcare System - Sistema Único de Saúde), Primary Healthcare has expanded from implementing healthcare networks, an organization form of services with centrality to primary care services. Due to the extension and heterogeneity of Brazilian municipalities, several organization forms of primary care services existed. In the city of São Paulo they were organized by three modalities of Basic Health Units. Thus, this study aimed to evaluate the care continuity in high-risk pregnancy care in different models of the basic health units. Methods:Data analysis defined performing prenatal care in primary care even after referral to the high-risk pregnancy service as the dependent variable. The independent variables were the sociodemographic and organizational aspects of health services. Logistic regression was used as the statistical technique. Results:Care is provided in a similar way in all basic health unit models, without prioritizing pregnant women with greater vulnerabilities (under 15 years and over 35 years, with education less than 7 years). Regarding women of black or brown color, it was observed that they were more likely (OR 1.997) to have care continuity in family health units. Home visiting and knowing the community health agent proved to be tools for organizing health services which are capable of producing better care. Conclusion: Primary healthcare services in Brazil for high-risk pregnancy care are organized without considering individual vulnerabilities. The home visits and the presence of the community health agent need to be strengthened in organizing the services, as they are able to modify the process of producing healthcare.