Methods: We conducted a retrospective review of prenatally diagnosed TOF infants admitted from 1/2004 to 6/2011. Aortic valve (AoV), pulmonary valve (PV), main pulmonary artery (MPA), and left and right pulmonary artery diameters were measured on the first fetal and neonatal echo and converted to z-scores based on gestational age (GA)(fetus) or body surface area (neonate). Subject details including need for prostaglandin (PGE) and timing of surgery were recorded. Associations between fetal and neonatal measurements were assessed using Pearson’s correlation coefficient. Differences between subjects who required neonatal surgery and those who did not were tested using a student’s ttest. Sensitivity and specificity of fetal echo z-scores to predict need for neonatal surgery were calculated using ROC curve.
Results: We identified 68 TOF infants born at 38.0±2.4 weeks GA with a fetal echo at a mean GA of 25.6±5.3 weeks. At neonatal echo, TOF/pulmonary atresia(PA) was present in 8(11.8%), TOF/PA with multiple aortopulmonary collaterals in 7(10.3%), and absent PV in 4(5.8%). We excluded TOF absent PV from analysis. There was a strong correlation between the fetal and neonatal AoV (r=0.35; p<0.01) and MPA z-scores (r=0.54; p<0.001). Of 64 patients, 19 were PGE dependent and required neonatal surgery. Subjects who required neonatal surgery had smaller fetal PV (-5.65±2.48 vs. -3.69±1.83; p<0.01) and MPA (-3.89±1.59 vs. -2.73±1.83; p<0.05) z-scores and smaller neonatal PV (-3.66±0.88 vs. -1.95±0.89; p<0.001) and AoV (3.48±1.32 vs. 2.59±1.66; p< 0.05) z-scores. A fetal PV z-score of -5 predicted need for neonatal surgery with 83% sensitivity and 80% specificity (p<0.001); PV z-score of -3.5 provided 92% sensitivity and 41% specificity.
Conclusion: In TOF, fetal PV and MPA z-scores are helpful in predicting the need for neonatal surgery. Patients with fetal PV z-score of less than -3.5 should be delivered at a tertiary care medical center.