Gestational diabetes is the one form of this well known, chronic disease of development that disappears. After the birth of the child, the mother's glucose levels typically return to normal. As a harbinger of things to come, gestational diabetes conveys greater risk for later type 2 (previously "non-insulin dependent") diabetes in both the mother and child. Thus, pregnant women have become a central target for prevention of this disease in the entire Pima population. Based on ethnographic interviews conducted between 1999 and 2000, I discuss the negotiated meanings of risk, "borderline" diabetes, and women's personal knowledge and experiences of diabetes, particularly during the highly surveilled period of pregnancy. I also highlight the heterogeneity of professional discourse pertaining to gestational diabetes, most notably the debate surrounding its diagnosis. Significantly, women's narratives reveal the same set of questions as is raised in the professional debate. Implications for diabetes prevention and for balancing the increased surveillance of pregnant women with clinical strategies that privilege their experience and perspectives are also discussed.