RESUMEN
BACKGROUND: The Brazilian Ministry of Health (MoH) recommends double screening (DS) for syphilis and HIV during the first and third trimesters of antenatal care (ANC) to mitigate vertical transmission. We surveyed DS outcomes and their associated factors in a priority Brazilian municipality with >100 000 inhabitants who face challenges for both health problems. METHODS: A total of 399 women were followed up throughout pregnancy using medical records. Spatial and multinomial logistic analyses were performed. RESULTS: There was an incidence rate of 24.8%, 59.4% and 15.8% for 'full DS', 'partial DS' and 'without DS', respectively. Younger women and those with a history of both prematurity and multiparity were less likely to be in the 'full DS' category. There was an overlap of high-density clusters of 'full DS' and 'ANC in better quality basic health units', adherent to both the Family Health Strategy and the National Program for Access and Quality Improvement in Primary Care. CONCLUSIONS: The poor DS outcomes presented in 75% of the cases were mostly linked to delays in starting ANC appointments or their discontinuity. Thus, the MoH recommendations, accompanied by ongoing training, technical assistance and the periodic evaluation of their implementation, need to effectively reach providers and promote counseling and awareness about the importance of DS for pregnant women.