Valve prostheses in pregnant women are considered to be a serious risk for management and maintenance of pregnancy.During the whole period of pregnancy such women are to receive anticoagulation therapy which may endanger the life of a mother and that of a foetus as well. It is well known that heparin does not pass the placenta and it is administered intravenously only.Low molecular heparin which can be administered subcutaneosly has been available to us for two years only. During the period from 1995 through 1997 at the Internal Clinic in Tuzla, we had managed to help three women with prosthetic valves to maintain their pregnancy.Two women had prosthetic mitral valves and one had a prosthetic aortic valve. Owing to incessant and careful keeping under observation of these women by our doctors and gynaecologists including maximum commitment of our nurses to work, these women are happy mothers now.