Analyzing the Ratio Between Prenatal Consultations and Live Births in Brazil: Spatial and Professional Patterns, 2008-2023.

This study analyzed the ratio between antenatal care visits and live births (LB) in Brazil as an indicator of service utilization intensity. This nationwide ecological longitudinal study combined descriptive temporal and spatial analyses of outpatient antenatal consultations recorded in SIA/SUS and LB reported in SINASC across Brazilian federative units and macroregions from 2008 to 2023. The ANC/LB ratio was interpreted as an indirect measure of the intensity of consultation utilization and recording relative to LB, rather than as an individual-level measure of antenatal care coverage or adequacy. An increase in the ANC/LB ratio was observed until 2014, followed by fluctuations and lower values from 2020 onward, with partial increases in some regions in subsequent years. Spatial analysis showed marked geographic variation, with higher ratios more frequently observed in the South and Southeast and lower values in several states in the North and Northeast. In 2023, nurses accounted for the largest proportion of antenatal consultations nationwide, particularly in the North and Northeast, whereas obstetrician-gynecologists had greater relative participation in the Southeast. Limitations include potential variation in the quality and completeness of SIA/SUS records, which may affect temporal and geographic comparability. These findings provide a nationwide perspective on the recorded intensity and professional composition of antenatal care and may support monitoring and health-service planning.