At the turn of the twentieth century, women across the Americas experienced increased scrutiny over their reproductive lives. The Brazilian city of Rio de Janeiro presents one crucial case study for understanding how the uneven process of modernization affected women's reproduction, and, in turn, how women negotiated these changes. This article explores police attitudes towards poor women's reproductive lives during Brazil's First Republic (1889–1930) and the early period of Getúlio Vargas's regime (1930–1937). During this time period, Brazil experienced a shift from familial to state patriarchy, and women's sexual lives—and honor—became public goods. I argue that police practice embedded patriarchal definitions of honor into modern judicial and societal attitudes toward women's bodies. As the state began controlling women's sexuality, the police played an active role defining and monitoring women's reproductive lives. But women actively negotiated police scrutiny over their reproduction in ways that complicated any monolithic consolidation of patriarchal norms.