Using the 3D printing technology, Doctors of University of Michigan successfully performed a surgery on a foetus. The unknown abnormality could have block the baby's airway at birth, but 3D Printed model of foetus face using MRI removed the guesswork of the surgery.
Source: http://www.webmd.com/baby/news/20151006/doctors-use-3d-printing-to-safeguard-baby-before-birth