This chapter discusses why medical professionals have wished to claim knowledge. It explores how they have gone about staking that claim, and how in the process they have constructed several new bodies. The chapter talks about a cyborg professional body with prosthetically enhanced senses and knowledge, a maternal body whose knowledge has been correspondingly discredited, a normal foetal body, or rather several racialized foetal bodies. As a consequence, these bodies may have changed the lived body experiences of millions of children, for better or for worse. When pregnant women attend an ultrasound examination, they are examined by or on behalf of physicians. Thus a prosthetically de-skilled maternal body is the second body constructed through routine obstetric ultrasound. Establishing the foetal nomogram has been a key to establishing this relationship. In order to bypass women's knowledge while seeing into their bodies, ultrasound-physicians have created a new, virtual foetal body: the normogram.