Cardiopulmonary bypass during pregnancy

Background: Cardiac surgery during pregnancy carries significant maternal and fetal risk and is typically considered after failure of medical therapy. We sought to determine the maternal and neonatal outcomes of cardiopulmonary bypass during pregnancy. Methods: Twenty-one pregnant patients undergoing cardiothoracic surgery were identified from the Mayo Clinic surgical database (1976 to 2009). Maternal and neonatal outcomes were reviewed. Results: Operations included 8 aortic valve replacements, 6 mitral valve repair-replacements, 2 myxoma excisions, 1 patent foramen ovale closure, 1 myectomy, 2 aortic aneurysm repairs, and 1 prosthetic aortic valve thrombectomy. Median cardiopulmonary bypass time was 53 minutes (range 16 to 185). Twelve patients (57%) required emergent surgery with a median gestational age (GA) of 25 weeks (range 7 to 35.5). Seven patients underwent cesarean section immediately prior to sternotomy delivering viable infants (median GA 31 weeks). In the remaining patients, three additional preterm births occurred, all in operations performed at an early GA (13 to 15 weeks). Median follow-up was 16 months (range 3 to 305). All patients improved to New York Heart Association functional class I or II. One early maternal death occurred 2 days after emergent mechanical aortic valve thrombectomy and 3 late maternal deaths occurred 2, 10, and 19 years postoperatively. Three fetal deaths occurred in mothers with additional medical comorbidities. Conclusions: In the current era, cardiothoracic surgery can be performed with relative safety during pregnancy. Fetal complications (prematurity and death) are associated with urgent, high-risk surgery, maternal comorbidity, and early GA. Emergent surgery appears to confer a higher risk of maternal death.