Pregnancy considerations in women with uncorrected tetralogy of Fallot

Abstract

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, accounting for approximately 7–10% of all congenital cardiac malformations. Although early surgical repair has transformed its natural history in high‐income settings, with contemporary long‐term survival exceeding 90%, uncorrected TOF continues to be encountered in pregnancy, particularly in women from resource‐limited regions or those with previously undiagnosed disease. The physiological adaptations of pregnancy, including reduction in systemic vascular resistance, plasma volume expansion, and a 30–50% rise in cardiac output, are poorly tolerated in the presence of a non‐restrictive ventricular septal defect and fixed right ventricular outflow tract obstruction, leading to progressive cyanosis, right ventricular strain, and uteroplacental hypoperfusion. Current European Society of Cardiology (ESC) guidance classifies unrepaired cyanotic heart disease without Eisenmenger syndrome as mWHO 2.0 class III, while Eisenmenger syndrome is classified as mWHO 2.0 class IV. Contemporary data from the ESC EORP Registry of Pregnancy and Cardiac Disease (ROPAC) report maternal mortality of 0.7% and heart failure in 8.7% of pregnancies with uncorrected congenital heart disease, with markedly worse outcomes in cyanotic subsets. This narrative review synthesizes the pathophysiology, risk stratification, obstetric management, intrapartum anesthetic considerations, comparative outcomes of uncorrected versus corrected disease, and key evidence gaps that continue to constrain care for this population, providing a physiology‐driven framework for the pregnancy heart team.