Pregnancy With Severe Pulmonary Regurgitation After Tetralogy Repair
A 29-year-old nulliparous woman with tetralogy of Fallot repaired in infancy via a transannular patch presents at 9 weeks' gestation. She is NYHA class II and works full time. Echocardiography shows free pulmonary regurgitation, no residual outflow obstruction, a right ventricular end-diastolic volume index of 168 mL/m² and a right ventricular ejection fraction of 36%. The left ventricle is normal. QRS duration is 158 ms, a 24-hour Holter shows no ventricular arrhythmia, and her six-minute walk is 70% of predicted. Resting saturation is 97%. She takes no cardiac medications and has never had a cardiac operation after infancy. She has read that 'pregnancy is fine after Fallot repair' and wishes to continue without changing her care.
1. How would you counsel her about maternal risk, and which specific findings drive your estimate?
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She falls into a moderate-to-high risk category (modified World Health Organization class III). Mortality is low in contemporary repaired tetralogy cohorts, but morbidity - heart failure, atrial and ventricular arrhythmia, prolonged hospital stay - is the real hazard, and her statement conflates a very heterogeneous population under one label.
Findings that drive the estimate:
- Right ventricular ejection fraction 36% and volume index 168 mL/m². Each independently predicts adverse events; both are beyond usual thresholds for intervention.
- QRS 158 ms. A marker of mechanical dyssynchrony and arrhythmia substrate; a wide QRS in a volume-loaded right ventricle is not benign in pregnancy.
- Free pulmonary regurgitation means the volume load rises further with the 40–50% plasma volume expansion of the second trimester.
- Baseline NYHA II usually deteriorates; preserved saturation, a negative Holter and a reasonable walk test are favourable but do not reclassify her.
Counsel with shared decision-making, present termination as a legitimate option without steering, and document that she was told the residual lesion - not the historical diagnosis - determines outcome.
2. She elects to continue. Detail surveillance, drugs to avoid, and delivery planning.
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Surveillance: baseline echocardiogram, electrocardiogram, brain natriuretic peptide, iron and thyroid studies. Visits every 4–6 weeks until 20 weeks, then every 2–3 weeks; echocardiography each trimester and before delivery; Holter for palpitations or if symptoms change. Watch specifically for exercise intolerance, new tricuspid regurgitation and atrial arrhythmia, which she will tolerate poorly.
Avoid: angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, sacubitril-valsartan, amiodarone and direct oral anticoagulants. Stop any of these now if present.
If atrial fibrillation or flutter develops: beta-blockade for rate, prompt electrical cardioversion if unstable, and therapeutic low-molecular-weight heparin with weight-based dosing and anti-Xa monitoring for at least three months.
Delivery: planned in a tertiary centre at around 39 weeks with cardiac anaesthesia and a congenital cardiologist present. Vaginal delivery with epidural is preferred; assist the second stage to avoid prolonged Valsalva. Caesarean section for obstetric indications, worsening heart failure or aortic disease - not for the diagnosis alone. Antibiotic prophylaxis is not required for vaginal delivery. Continue close monitoring for 72 hours postpartum, when fluid mobilization and haemorrhage are the main threats.
3. Six weeks postpartum her ejection fraction is 32% and volume index 190 mL/m². She asks about a second pregnancy and about contraception. What do you advise?
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Answer the two questions separately.
Second pregnancy: she now meets conventional criteria for pulmonary valve replacement (symptomatic severe regurgitation with marked right ventricular dilatation and dysfunction), and her ventricle has not remodelled. Another pregnancy in this state carries substantially higher risk. Recommend valve replacement first, but be honest about the trade-offs: a bioprosthesis degenerates faster in a young woman, and pregnancy after replacement is safer but not risk-free. If she declines surgery and pursues pregnancy anyway, document the discussion and arrange early tertiary care.
Timing: repeat imaging at 3–6 months postpartum, because some reverse remodelling occurs after delivery. Do not commit to surgery on the six-week numbers alone unless she is unstable.
Contraception: progestin-only pill, subdermal implant or levonorgestrel intrauterine device are preferred. Estrogen-containing agents add thrombotic risk in a patient with a dilated, dysfunctional right ventricle and atrial arrhythmia substrate, and should generally be avoided. Address emergency contraception and ensure she leaves with a plan in place, not a referral.