Oct. 26, 2024
Cardiovascular disease is a leading cause for maternal mortality. The physiological changes that occur to support the increased demands of the pregnancy put stress on the cardiovascular system. More people with congenital heart disease are reaching childbearing age, and the number of pregnant patients with acquired heart disease is increasing.
With a rising potential risk of heart disease in expectant patients, is surgery safe during pregnancy? Limited data existed on maternal and fetal outcomes of cardiac surgery during pregnancy. Now, a 40-year retrospective review published in the Annals of Thoracic Surgery is added to the literature.
Mayo Clinic cardiac surgeons analyzed data in a single-center review of cardiac surgery in pregnancy. Cardiac surgeons identified 29 pregnant patients from the Mayo Clinic surgical database who underwent surgery using cardiopulmonary bypass (CPB).
"This is the largest series to date of surgery during pregnancy, and based on the data provides both an estimate of risk to help counsel families, as well as guidance in terms of delivery timing relative to the cardiac surgery. Both this study and our review of techniques for surgery during pregnancy provide information on how to optimize the health and well-being of both mother and baby," says Elizabeth H. Stephens, M.D., Ph.D., a cardiovascular surgeon at Mayo Clinic in Rochester, Minnesota, specializing in congenital cardiac surgery, and one of the study's authors.
"Decisions regarding cardiac surgery in pregnancy are complex, and this study offers evidence on timing of surgery in that it supports the notion that in a viable pregnancy, a cesarean section prior to cardiopulmonary bypass surgery may improve fetal outcomes. In addition, it details our current practice of management of this patient population," says Katie A. Young, M.D., a cardiologist, co-director of the Cardiovascular Obstetrics Clinic at Mayo Clinic in Rochester, Minnesota, and senior author of the study. "My hope is that this study helps provide a framework and support for those who care for high-risk patients with cardiac disease in the complex decision-making process."
Key findings
Whenever possible, management of cardiac pathology during pregnancy is medical in nature or at times entails catheter-based interventions. In select scenarios, cardiac surgery is necessary. Over the 40-year period, the cardiac surgery was rarely needed.
In this series, CPB surgery was associated with:
- Low early maternal mortality.
- Significant fetal mortality.
- High rate of preterm deliveries.
However, with advancements in cardiovascular surgical techniques, obstetric care and technology, the maternal risk of cardiovascular surgery during pregnancy is low. "While maternal mortality is similar to those who are not pregnant having bypass surgery, fetal mortality and preterm deliveries remain high, even at a very experienced center as our own," says Dr. Young.
Study highlights:
- Twenty-nine pregnant patients with a median age of 28 years underwent cardiac surgery using cardiopulmonary bypass at a median gestation of 25 weeks.
- Surgery was performed in the first trimester for three patients (10%), second trimester for 16 (55%) and third trimester for 10 (35%).
- There was one (3%) maternal death two days after mechanical aortic valve thrombectomy and five (17%) fetal losses.
- Fourteen patients who underwent cardiac surgery using CPB with continuing pregnancy experienced a 29% fetal mortality rate, and seven patients underwent delivery before surgery and experienced 14% fetal mortality.
- In cases of fetal loss, surgery was performed at a median of 25 weeks (IQR, 21 to 26 weeks) compared with a median of 23 weeks (IQR, 20 to 29 weeks) in cases without fetal loss (P = 0.55).
"We found that fetal death occurred more commonly when delivery occurred after cardiac surgery compared to before, suggesting that delivery should occur prior to cardiac surgery whenever possible," says Dr. Stephens.
Preconception counseling
Patients with preexisting cardiac disease, congenital or acquired, need guidance from a multidisciplinary pregnancy heart team for preconception counseling and management. "Though cardiac surgery in pregnant patients is rare, preconception counseling is important. Refer patients with cardiac disease contemplating pregnancy to a cardio-obstetric team for assessment and counseling. High-risk patients are best served with management at or involvement with a quaternary referral center," says Dr. Young.
Next steps
With the infrequency and complexity of these cases, it is important to share information. "Additional studies and collaboration are needed to improve our understanding and management of this patient population," says Dr. Young.
"Continued research is needed to understand aspects of the cardiac surgery and bypass that posed a risk to the fetuses, and how to mitigate that risk," says Dr. Stephens.
For more information
Schmitz KT, et al. Is cardiac surgery safe during pregnancy? A 40-year single institution experience. The Annals of Thoracic Surgery. In press.
Refer a patient to Mayo Clinic.