Background: An open heart surgical procedure performed on a pregnant woman is a great challenges for the surgeon, mother and the fetus. Especially, first and second trimesters brings unpredictable risks for the fetus. There isn’t a consensus on the subject and large series are not available. Here we present a case of an emergency open heart surgery on a pregnant woman at her 18th week of gestation.
Case report: A 28 year old woman was operated under cardiopulmonary bypass in emergency conditions due to the acute thrombosis of a mechanical prosthetic valve, who was at 18th week of her gestation. Mitral valve re-replacment was performed with mild hypothermia (33°C) and high
pump output and a porcine bioprosthesis was implanted at mitral position. Operation was successful, and no appearent harm was done to fetus. She was discharged from hospital on 7th postoperative day. Her outpatient clinic examination revealed normal findings of the patient and the fetus.
Conclusions: Avoiding deeper hypothermic degrees and low pump output, and maintaining blood pressure over 70mmHg during cardiopulmonary bypass seems to be safe for the fetus in the second trimester. There are many ethical and scientific issues to be discussed for the kind of prosthetic
valve to be re-implantated in a pregnant woman. Becuse it doesn’t need any anti-coagulation, and has better hemodynamic properties compared to mechanical valves, we believe that biological tissue valves serves better, and can be used for these kinds of situations, after the patients approval, since their long-term durability is a matter of concern.

Keywords: Pregnancy, heart valve disease, acute thrombosis of mechanical cardiac prosthesis