Table 1.

Eligibility criteria for the systematic review.

Variables	Inclusion criteria	Exclusion criteria
Study design	Cross-sectional, longitudinal, or case-control studies conducted in Brazil Studies based on primary data	Reviews, opinion articles, editorials, or publications without primary data or not peer-reviewed The most complete and recent data will be used if studies report the same data in multiple sources [19,20].
Population and location	Studies in which the sample involved pregnant women or newborns with syphilis Studies with residents in Brazil	Studies with samples involving other populations (nonpregnant women or men)
Outcomes	Studies reporting the prevalence or incidence of Treponema pallidum (syphilis) infection or its risk or associated factors in pregnant women or neonates Studies that diagnosed syphilis based on direct pathogen detection tests or through immunological, treponemal, or nontreponemal tests, in accordance with Brazilian protocols for diagnosing syphilis [2]	Studies presenting the incidence or prevalence of combined infections (ie, syphilis with other sexually transmitted infections) and not allowing isolated analysis
Language	—a	No restriction regarding language or year of publication
Time frame	—	No restriction regarding to year in which the study was carried out or published

^aNot applicable.