Serial echocardiography assessment and clinical outcomes among pregnant women with Tetralogy of Fallot
Authors: Hon N W L , Wu M Z , Yu S Y , Wong P F , Tse Y K , Li H L , Tsui L H , Yu S Y , Yiu K H 
Published: February 2022

Funding Acknowledgements

Type of funding sources: None.

Following advancements in intracardiac repair of Tetralogy of Fallot (TOF), a greater proportion of patients survive well beyond child-bearing age. Pulmonary regurgitation (PR) and subsequent progressive right ventricular dilatation occur frequently as an intrinsic complication of surgical repair of TOF. High-output states such as pregnancy may exacerbate these late complications. The advocation of pre-pregnancy pulmonary valve replacement to mitigate pregnancy-related cardiac burden has remained controversial. This study aims to delineate the outcomes of pregnancy among women with repaired TOF.

105 pregnant episodes among were identified from a cohort of 240 adult female patients with TOF between 1990 to 2021. Patients with echocardiographic studies performed within 1 year prior to and following delivery were included for cardiac functional analysis. A paired sample t-test was performed to compare echocardiographic parameters between pre-delivery and post-delivery periods. Linear regression was used to identify changes to identify significant changes in echocardiographic parameters among patients with a baseline of severe PR.

Within all pregnant episodes (n = 105), 65 successful pregnancies, 16 spontaneous miscarriages, 21 termination of pregnancies and 3 ectopic pregnancies were recorded. The mean maternal age was 28.9 (±6.7) years with deliveries at 37.86 (30-41) gestational weeks. Cardiovascular events occurred in 19 pregnancies with 4 patients having gestational hypertension, 4 patients with pre-eclampsia toxemia, 7 patients with heart failure symptoms and 4 patients with arrhythmias. Other complications included 4 patients with gestational diabetes mellitus, 3 patients with impaired glucose tolerance, 2 patients with anemia, 3 patients with maternal thyroid disease and 1 patients with proteinuria.

Echocardiographic studies demonstrated significant changes in left ventricular ejection fraction (LVEF) (Pre-delivery = 60.69 ±8.73; post-delivery = 59.39 ±9.36) (P = 0.007), left ventricular end diastolic volume (LVEDV) (Pre-delivery: 89.71mL ±18.22mL; Post-delivery: 80.96mL ±12.32mL; P = 0.007), left end systolic volume (LVESV) (Pre-delivery: 35.43 ±12.36; Post-delivery: 32.70 ± 8.83; P = 3.7x10-5) and right ventricular index of myocardial performance score (Pre-delivery: 0.34 ±0.12; Post-delivery: 0.33 ±0.12; P = 0.007). Patients with severe PR was found to have significantly worse right ventricular global longitudinal strain (RV GLS) (P = 0.029). 2 patients progressed to severe PR following delivery.

Adult female patients with TOF can have viable pregnancies with acceptable mortality and morbidity. Deterioration in echocardiographic parameters were identified when comparing between pre-delivery and post-delivery studies. TOF patients should be closely monitored throughout and post-delivery for detection of deterioration of cardiac function and clinical symptoms.