Supplementary Material for: INCREMENTAL VALUE OF FETAL STRAIN ECHOCARDIOGRAPHY IN THE PREDICTION OF NEED FOR NEONATAL VALVULOPLASTY IN ISOLATED PULMONARY VALVE STENOSIS

Introduction
Pulmonary valve stenosis (PS) is a common congenital heart defect with variable severity. Prenatal echocardiography has limited ability to predict neonatal valvuloplasty. We aim to evaluate the prediction accuracy of fetal echocardiography including 2D speckle tracking echocardiography (2D-STE).
Methods
A prospective cohort study including 24 cases of isolated PS (7 critical, 17 mild-moderate) and 48 gestational-age-matched healthy controls was conducted at BCNatal. Cases were matched with 48 healthy controls adjusted by gestational age at echocardiography. Comprehensive fetal echocardiography and 2D-STE were performed diagnosis.

Results
Median gestational age at echocardiography was 32.5 weeks (27.4-35.4). Half of the PS fetuses underwent valvuloplasty within the first month of life.
PS fetuses showed impaired right ventricular function (reduced tricuspid annular plane systolic excursion, more pulsatile ductus venosus), with preserved left ventricular function. Four independent predictors were identified: ductus venosus pulsatility index ≥79th centile, right ventricular global longitudinal strain ≥-15.9%, reversed flow in the ductus arteriosus, and significant tricuspid regurgitation. When combined into a simple 4-point score, values  2 predicted valvuloplasty with 91.7% sensitivity and 100% specificity (AUC: 0.931).

Conclusion
These findings suggest that a fetal echocardiographic score may accurately identify fetus with PS needing early postnatal valvuloplasty, allowing improved perinatal management. Further validation studies are needed.