To evaluate the value of fetal echocardiography in assessing the severity and prognosis of isolated pulmonary valve stenosis (PS).

A retrospective analysis was conducted on 79 fetuses with PS diagnosed by fetal echocardiography and confirmed by postnatal echocardiography between January 2019 and January 2024 at the First Affiliated Hospital of Hebei North University and Hebei Reproductive and Obstetrics Hospital. According to the severity of PS on postnatal echocardiography, the fetuses were divided into a mild PS group (n=38), a moderate PS group (n=22), and a severe PS group (n=19). Fetal echocardiographic parameters measured included pulmonary valve velocity (PVV), right-to-left ventricular diameter ratio (RV/LV), tricuspid regurgitation velocity (VTR), cardiothoracic ratio (C/T), main pulmonary artery-to-aorta diameter ratio (MPA/AO), tricuspid valve inflow duration-to-cardiac cycle ratio (TVI/CC), and tricuspid-to-mitral valve annular diameter ratio (TV/MV). Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive performance of these parameters for perinatal outcomes.

Fetal echocardiographic findings showed no significant right ventricular remodeling in the mild PS group, mild remodeling with slightly increased thickness and diameter in the moderate PS group, and severe remodeling with reversed ductus arteriosus (DA) flow in the severe PS group. With increasing PS severity, C/T, PVV, and VTR increased significantly, while MPA/AO, RV/LV, TV/MV, and TVI/CC decreased progressively, with overall differences among the three groups being statistically significant (P<0.05). No reversed DA flow was observed in the mild and moderate groups; in the severe group, 100% (19/19) of fetuses had reversed DA flow. The use of prostaglandin E1 increased significantly with PS severity: 0 in mild, 4.55% (1/22) in moderate, and 57.89% (11/19) in severe cases. Percutaneous balloon pulmonary valvuloplasty rates were significantly higher in the moderate (45.45%, 10/22) and severe PS groups (78.95%, 15/19) compared with the mild group (15.79%, 6/38) (P<0.001). Mortality was 0 in both the mild and moderate groups but 10.53% (2/19) in the severe group. In patients with composite adverse outcomes, PVV was significantly higher, and RV/LV and TV/MV were significantly lower than those in patients with non-composite adverse outcomes (P<0.05). The area under the ROC curve values of PVV, TV/MV, and RV/LV for predicting composite adverse outcomes were 0.824, 0.782, and 0.750, respectively; the AUC of the three parameters combined was 0.919.

Fetal echocardiographic parameters can effectively assess the severity of isolated PS, predict perinatal outcomes. facilitate early identification of high-risk fetuses, and provide a scientific basis for individualized perinatal management and intervention strategies, thereby improving fetal prognosis.