This study of “birth technologies” such as amniocentesis and ultrasound explores their relationship to law in a correlative area, abortion politics, in order to assess the indirect influence of politics on technology. We begin nearly twenty years ago when these technologies were emerging and trace the story to the early 1990s. Our analysis suggests that abortion politics, filtered through such activities as grant-making and basic research, influenced the development of these technologies. We therefore propose a model of policy that includes both the relatively independent march of scientific research and technical applications and the operation of constraining forces, like political interests, on science and technique. Here, law is a vehicle that itself becomes illuminated as both politics and substance.