Cardiac surgery in pregnancy.

The need for cardiac surgery during pregnancy is rare. Only 1% to 4% of pregnancies are complicated by maternal cardiac disease and most of these can be managed with medical therapy and lifestyle changes. On occasion, whether owing to natural progression of the underlying cardiac disease or precipitated by the cardiovascular changes of pregnancy, cardiac surgical therapy must be considered. Cardiac surgery is inherently dangerous for both, the mother and fetus with mortality rates near 10% and 30%, respectively. For some conditions, percutaneous cardiac intervention offers effective therapy with far less risk to the mother and her fetus. For others, cardiac surgery, including procedures that mandate the use of cardiopulmonary bypass, must be entertained to save the life of the mother. Given the extreme risks to the fetus, if the patient is in the third trimester, strong consideration should be given to delivery before surgery involving cardiopulmonary bypass. At earlier gestational ages when this is not feasible, modifications to the perfusion protocol including higher flow rates, normothermic perfusion, pulsatile flow, and the use of intraoperative external fetal heart rate monitoring should be considered.