145. ACHD: Pregnancy and Congenital Heart Disease with Dr. Carole Warnes

CardioNerds (Amit Goyal and Daniel Ambinder), ACHD series co-chair Dr. Agnes Koczo (UPMC), and ACHD FIT lead Dr. Katia Bravo (UCLA) join ACHD expert Dr. Carole Warnes (Professor of Medicine and founder of the Adult Congenital Heart Disease Clinic at Mayo Clinic), to discuss adult congenial heart disease and pregnancy. They cover preconception counseling in women with congenital heart disease, appropriate risk stratification to estimate maternal and neonatal morbidity using existing tools and an individualized care approach and preparation for a multidisciplinary delivery plan. Audio editing by CardioNerds Academy InternDr. Leticia Helms.

The CardioNerds Adult Congenital Heart Disease (ACHD) series provides a comprehensive curriculum to dive deep into the labyrinthine world of congenital heart disease with the aim of empowering every CardioNerd to help improve the lives of people living with congenital heart disease. This series is multi-institutional collaborative project made possible by contributions of stellar fellow leads and expert faculty from several programs, led by series co-chairs, Dr. Josh SaefDr. Agnes Koczo, and Dr. Dan Clark.

The CardioNerds Adult Congenital Heart Disease Series is developed in collaboration with the Adult Congenital Heart Association, The CHiP Network, and Heart University. See more

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PearlsNotesReferencesGuest ProfilesProduction Team


  1. Women with congenital heart disease can safely carry a pregnancy if appropriate risk stratification and management is performed by an expert multidisciplinary cardio-obstetrics team.
  2. There are a myriad of hemodynamic and vascular changes which impact congenital cardiac physiology and evolve throughout the different stages of pregnancy. Therefore, planning is key. An evaluation of heart rate response to exercise and optimization of potential factors that could worsen during pregnancy, such as arrhythmias, are recommended.
  3. Maternal morbidity & mortality risk-stratification systems such as the modified WHO, CARPREG or ZAHARA criteria are helpful starting points. Ultimately, each patient requires individualization given the heterogeneity that exists among congenital heart defects.
  4. Vaginal delivery is generally preferred over C-section from a cardiac standpoint. An assisted second stage of labor during the period of greatest hemodynamics changes should also be considered if vaginal delivery is pursued.

Show notes

1. Why is preconception counseling important in women with congenital heart disease and what does it entail?

  • Ensuring women with congenital heart disease are optimized prior to conception decreases maternal and neonatal complications. For this reason, preconception counseling is paramount for these patients.
  • In addition, counseling leads to patients making more informed decisions about family planning.
  • The integral parts of preconception counseling include: (1) discussing the current anatomical and physiological status, (2) discussing possible complications during pregnancy specific to the patient’s congenital heart defect (with genetic counseling referral if appropriate), (3) evaluating cardiac medications, taking into account benefits vs teratogenic potential, (4) discussing and planning for necessary pre-pregnancy tests or interventions (exercise stress testing is an important tool in evaluating how the patient will tolerate the stressors of pregnancy), (5) organizing antepartum care with high-risk obstetrics teams, (6) discussing location, timing and mode of delivery, (7) discussing alternative options to carrying a pregnancy in women who are at extreme risk (ie Fontan physiology, Eisenmenger syndrome) and (8) discussing postpartum contraception. 

2. How do we risk stratify women with congenital heart disease who are contemplating pregnancy?

An expert evaluation by an ACHD specialist is recommended using a thorough clinical and hemodynamic assessment centered around the individual patient and her values. Several risk prediction tools are available and should be used as a starting point. These include the modified World Health Organization (mWHO) classification, risk factors derived from CARPREG II (CARdiac disease in PREGnancy II), and ZAHARA (acronym based on Dutch translation for Pregnancy in congenital heart defects – Zwangerschap bij Aangeboren HARtAfwijkingen I) studies. 

  • The mWHO classification groups congenital hearts conditions into class I to IV, with higher classes indicating higher predicted risk of cardiovascular maternal morbidity and mortality.
  • The CARPREG II risk prediction index assigns points based on a number of different predictors including prior cardiac events or arrhythmias, baseline New York Heart Association Class III-IV or cyanosis, presence of a mechanical valve, ventricular dysfunction, high risk left-sided valve disease or left ventricular outflow tract obstruction, pulmonary hypertension, and coronary artery disease or high-risk aortopathies.
  • The ZAHARA risk score also considers sub-pulmonary atrioventricular valve regurgitation and cardiac medications before pregnancy as additional risk factors as well.

3. What are the potential fetal/neonatal risks associated with pregnancy in congenital heart conditions?

Some of the risks include spontaneous abortion, premature birth, small for gestational age neonate, and congenital heart disease in the baby (which may be different than maternal CHD (see Table 1). Most of these are related to maternal heart failure; however other complications such as arrhythmias, endocarditis, thromboembolic events, and medication adverse effects predispose to neonatal complications. Specifically, women with uncorrected cyanotic heart disease and pulmonary hypertension with saturation levels ≤ 85% reach a live birth rate of only 12%.

Table 1. Recurrence rate for congenital heart lesions in affected mothers.

LesionRecurrence rate
Atrial septal defect4-6%
Ventricular septal defect6-10%
Atrioventricular septal defect11.5-14%
Coarctation of the aorta4-6.5%
Left ventricular outflow tract obstruction8-18%
Right ventricular outflow tract obstruction4-6.5%
Tetralogy of Fallot2-2.5%
Transposition of the great arteries2%
Congenitally corrected transposition of the great arteries3-5%
Univentricular hearts21%

What should a multidisciplinary delivery plan include?

Detailed delivery planning should be undertaken prior to expected delivery date to plan for obstetric anesthesia and analgesia, inpatient peripartum management (level of acuity, need for bubble filters in cases of shunts, avoidance of excessive volume load, infective endocarditis prophylaxis, mode of delivery), as well as postpartum care and discharge planning  including post-partum contraception.

Maternal and Neonatal Risk by Congenital Lesion

AnatomyMaternal RiskFetal/ Neonatal riskPoints to consider
Right ventricular outflow tract obstruction or regurgitation– Increased pregnancy-induced preload can promote RV dilatation and heart failure– Preterm labor – Small for gestational ageUsually well tolerated during pregnancy
Left-sided obstructive lesions– Heart failure in patients with severe symptomatic AS with volume expansion in pregnancy  – Small for gestational ageBalloon valvuloplasty in severe, symptomatic cases
Systemic right ventricle– Heart failure – Atrial arrhythmias – Worsening systemic tricuspid regurgitation– 25-50% prematurity – Small for gestational ageSystemic RV function may be impacted by repeat pregnancies
Coarctation of the aorta– Hypertensive disorders of pregnancy – Heart failure– Small for gestational age– Hormonal changes may impact aortic vasculature into the postpartum period
Ebstein’s anomaly– Cyanosis – Arrhythmias can be triggered by increased preload  – Related to maternal oxygen saturation– Use bubble filters to avoid paradoxical emboli (high coexistence of ASD)
Fontan circulation– Atrial arrhythmias can be triggered by increased preload – Thromboembolism due to hormonal changes – Discuss termination of pregnancy in failing Fontan  – 40-70% prematurity – Small for gestational ageBaseline oxygen saturation is the most important marker for fetal outcomes.
Eisenmenger syndrome   Also see Episode #124 – Pregnancy & Pulmonary Hypertension with Dr. Candice Silversides  – Mortality 20-40%. – Discuss termination of pregnancy-Right ventricular failure from increased preload -Thromboembolism due to hormonal changes
Aortopathy   Also see Episode #126 – Pregnancy & Aortic Disorders with Dr. Nupoor Narula– Hormonal changes impact aortic vasculature and can led to accelerated aortic enlargement – 10% risk aortic dissection risk (usually third trimester or postpartum) in Marfan syndrome with root diameter >40 mm, rapid dilation or previous dissection of the ascending aorta– 15% premature delivery due to premature rupture of membranes. – In cases of dissection, fetal demise can occur.Prophylactic aortic root replacement considered before pregnancy if diameter >40 mm, or smaller with rapid increase in dimensions, family history of dissection, or concomitant severe AI


  1. Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. Apr 2 2019;139(14):e698-e800. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000603
  2. European Society of G, Association for European Paediatric C, German Society for Gender M, et al. ESC Guidelines on the management of cardiovascular diseases during pregnancy: the Task Force on the Management of Cardiovascular Diseases during Pregnancy of the European Society of Cardiology (ESC). European heart journal. Dec 2011;32(24):3147-3197. https://academic.oup.com/eurheartj/article/39/34/3165/5078465
  3. Pierpont ME, Brueckner M, Chung WK, et al. Genetic Basis for Congenital Heart Disease: Revisited: A Scientific Statement From the American Heart Association. Circulation. Nov 20 2018;138(21):e653-e711. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000606
  4. Elkayam U, Goland S, Pieper PG, Silversides CK. High-Risk Cardiac Disease in Pregnancy: Part II. Journal of the American College of Cardiology. Aug 2 2016;68(5):502-516. https://www.jacc.org/doi/full/10.1016/j.jacc.2016.05.048

Meet Our Collaborators!

Adult Congenital Heart Association
Founded in 1998, the Adult Congenital Heart Association is an organization begun by and dedicated to supporting individuals and families living with congenital heart disease and advancing the care and treatment available to our community. Our mission is to empower the congenital heart disease community by advancing access to resources and specialized care that improve patient-centered outcomes. Visit their website (https://www.achaheart.org/) for information on their patient advocacy efforts, educational material, and membership for patients and providers

CHiP Network

The CHiP network is a non-profit organization aiming to connect congenital heart professionals around the world. Visit their website (thechipnetwork.org) and become a member to access free high-quality educational material, upcoming news and events, and the fantastic monthly Journal Watch, keeping you up to date with congenital scientific releases. Visit their website (https://thechipnetwork.org/) for more information.

ChiP Network

Heart University
Heart University aims to be “the go-to online resource” for e-learning in CHD and paediatric-acquired heart disease. It is a carefully curated open access library of educational material for all providers of care to children and adults with CHD or children with acquired heart disease, whether a trainee or a practicing provider. The site provides free content to a global audience in two broad domains: 1. A comprehensive curriculum of training modules and associated testing for trainees. 2. A curated library of conference and grand rounds recordings for continuing medical education. Learn more at www.heartuniversity.org/

Heart University

Guest Profiles

Dr. Carole Warnes
Dr. Carole Warnes

Carole A. Warnes, M.D., is a cardiologist in the Division of Structural Heart Disease, Department of Cardiovascular Medicine with a joint appointment in the Division of Pediatric Cardiology at Mayo Clinic. Dr. Warnes joined the staff of Mayo Clinic in 1987 and founded the Adult Congenital Heart Disease Clinic, which she directed for 27 years. She holds the academic rank of professor of medicine. She is recognized with the distinction of the Penske Foundation Professorship in Clinical Medicine in Honor of Ian D. Hay, M.D., Ph.D., and J. Eileen Hay, M.B., Ch.B.

Dr. Warnes completed her M.B., B.S. at Newcastle Upon Tyne Medical School in the United Kingdom and did her general medicine training in Newcastle. She was registrar in cardiology at both the London Chest Hospital and the National Heart Hospital in London. Dr. Warnes was visiting staff associate in cardiology at the National Institutes of Health and a British Heart Foundation research fellow at the National Heart Hospital. She received her postgraduate M.D. degree with commendation at Newcastle Upon Tyne Medical School. In 2005 she was made a fellow of the Royal College of Physicians (FRCP).

As a cardiologist, Dr. Warnes focuses on adult congenital heart disease, and she oversees the treatment of many patients with difficult cases, including those related to heart disease and pregnancy. She speaks internationally and nationally on these topics and has published three books and more than 200 papers in prominent peer-reviewed journals. She has served as an editorial board member for American Journal of Cardiology, Circulation and Heart. In 2008 she chaired the American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for the Management of Adults with Congenital Heart Disease. She has held multiple leadership roles in addition to serving on many committees of the ACC and served on their Board of Trustees for seven years. In 2016 she received the Distinguished Fellowship Award from ACC.

Dr. Warnes is the recipient of the Heart Heroes Leadership Award from the Adult Congenital Heart Association and received the Henry S. Plummer Distinguished Physician Award from Mayo Clinic. She has been honored consistently as Outstanding Teacher of the Year in the Cardiovascular Division at Mayo Clinic, where she was also recognized with the Distinguished Educator Award in 2010 and the Lifetime Achievement for Outstanding Contributions to Medical Education in 2014. In 2015 she received the Laennec Master Clinician Award from the AHA.

Dr. Warnes provides mentorship to numerous fellows and for 10 years served as dean of Mayo Clinic School of Continuing Medical Education. She holds teaching/examining privileges in Clinical and Translational Science at Mayo Clinic Graduate School of Biomedical Sciences.

Dr. Katia Bravo
Dr. Katia Bravo

Dr. Katia Bravo-Jaimes (@Bravo__MD) is an Adult Congenital Heart Disease Fellow at the University of California, Los Angeles. She is interested in reducing disparities in congenital heart disease care at local, national and global levels. She plans to continue her academic career combining clinical care, education and collaborative research to help patients with congenital heart disease reach their full potential.

CardioNerds Adult Congenital Heart Disease Production Team

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