Cardiac surgery during pregnancy.

Cardiovascular adaptations during pregnancy are normally well tolerated in healthy women. However, 2% to 4% of women of childbearing age have some degree of concomitant heart disease, and these changes may compromise cardiac function. Of these, a few who do not respond to medical treatment may require surgical correction. In this setting, maternal mortality rate has improved to levels similar to those in non-pregnant counterparts. However, the fetal mortality rate remains high (up to 33%). Factors contributing to high fetal mortality rates include the timing of the operation, the urgency of the operation, and the fetal/fetoplacental response to cardiopulmonary bypass. Modulation of the fetoplacental response to cardiopulmonary bypass may prevent placental dysfunction and sustained uterine contractions, which underlie fetal hypoxia and acidosis.In this article, we review cardiovascular adaptations to pregnancy and the pathophysiologic effects of cardiopulmonary bypass on the mother, fetus, and fetoplacental unit, and we talk about whether manipulation of these responses can help in improving fetal outcome. Finally, approaches regarding perfusion management and off-pump cardiac surgical techniques in pregnancy are discussed.