Abstract
The medical marketplace is populated by a diverse array of users, producers, mediators, and commentators. While historians of technology have previously highlighted the role that "mediators" play in the broader consumer marketplace, little attention has been paid to how such intermediaries, like medical professionals and government regulators, impact the diffusion and uptake of new medical instruments and procedures. In the medical marketplace, mediators make decisions about what technologies should be available when and to whom. They may also choose to provide or promote certain techniques over others for a variety of personal, professional, and experiential reasons. This paper uses a historical case study of two competing prenatal diagnostic techniques, amniocentesis and chorionic villus sampling, to examine the dual role of mediators, potential users, and media commentators within the medical marketplace in promoting as well as impeding, the availability and uptake of new medical technologies.