This research highlights the malleability of Maternal Mortality Ratios (MMR) and the ways in which they accommodate a variety of narratives via their claims about women's access to reproductive health services. MMR plays an important role in determining fiscal and legislative priorities for women's health in Mexico and in the discursive practices that shape societal beliefs about appropriate birthing practices and birth attendants. This paper is based on ethnographic fieldwork conducted in Yucatán and Quintana Roo between 2009 and 2017 during Ministry of Health midwifery workshops and approximately fifty interviews with midwives, doctors, public health officials, and parents. It explores the mutability of MMR within the context of political struggles for midwifery in Mexico-both for and against its legality and existence. In Mexico, MMR is often used by bureaucrats and public health workers to reinforce the importance of biomedical obstetric services over midwifery. However, the same metrics are also employed by midwives in critiques of underfunded and often structurally-violent maternal health care services. While doctors attempt to use MMR to prove that birth is inherently dangerous and must take place in hospitals with access to obstetric technologies and interventions, midwives use MMR to demonstrate that birth in hospitals is risky precisely because of those technologies and their inappropriate use, and to draw international attention and funding in support of midwifery. In addition to examining the strategic use of MMR in health-related discourses, this paper interrogates techniques employed by the state to limit midwives' access to births in the name of monitoring and improving MMR. I contend that while discursive uses of MMR to advance professional and political goals are common in both midwifery and biomedicine, the asymmetric power relations of biomedicine vis-à-vis the Mexican state privilege interpretations of MMR that justify and legitimate enhanced bureaucratic surveillance of midwives.