A Miscarriage of Justice examines women's reproductive health in relation to legal and medical policy in Rio de Janeiro, Brazil. After the abolition of slavery in 1888 and the onset of republicanism in 1889, women's reproductive capabilities—their ability to conceive and raise future citizens and laborers—became critical to the expansion of the new Brazilian state. Analyzing court cases, law, medical writings, and health data, Cassia Roth argues that the state's approach to women's health in the early twentieth century focused on criminalizing fertility control without improving services or outcomes for women. Ultimately, the increasingly interventionist state fostered a culture of condemnation around poor women's reproduction that extended beyond elite discourses into the popular imagination. By tracing how legal thought and medical knowledge became cemented into law and clinical practice, how obstetricians, public health officials, and legal practitioners approached fertility control, and how women experienced and negotiated their reproductive lives, A Miscarriage of Justice provides a new way of interpreting the intertwined histories of gender, race, reproduction, and the state—and shows how these questions continue to reverberate in debates over reproductive rights and women's health in Brazil today.