Hi, welcome to healthcaremagic. I completely understand your concern and happy to tell you that warfarin only affects baby when it is/was taken by mother and not by father. In support to your research, warfarin given to mother during pregnancy, increases birth defects, like skeletal abnormalities (also termed as foetal warfarin syndrome- hypoplasia of nose, eye socket, hand bones, and growth retardation). It can also cause CNS defects, foetal hemorrhage, foetal death. Hope this will help you.