Objective: To explore the predictive value of prenatal ultrasound characteristics of fetal constriction of the aorta (CoA) in postpartum neonatal outcomes. Methods: A total of 128 pregnant women with fetal CoA indicated by prenatal ultrasound who underwent regular prenatal examinations were enrolled, and all were followed up till 0~2 years old after fetal birth. According to echocardiographic diagnosis and surgical confirmation after birth, neonatal outcomes were divided into group A (significant constriction) and group B (mild constriction + normal). The maternal and neonatal general data and prenatal ultrasonogram characteristics [ascending aortic diameter (AAO), distal transverse aortic arch (DTAA), flow velocity at the stenosis site] in the two groups were compared. The relationship between AAO, DTAA, flow velocity at the stenosis site and significant CoA was analyzed by Logistic regression analysis, and predictive value of AAO, DTAA, flow velocity at the stenosis site and combined detection in significant CoA was analyzed by ROC curves. Results: Among 128 pregnant women after follow-up, there were 11 cases with normal neonates, 31 cases with mild constriction and 86 cases with significant constriction. The age of puerperae, gestational weeks detected by ultrasound, BMI and proportion of gestational diabetes mellitus in group A were higher than those in group B(P<0.05). AAO and DTAA in group A were lower than those in group B, and flow velocity at the stenosis site was faster than that in group B(P<0.05). After correcting the influences of age, gestational age detected by ultrasound, BMI and the proportion of gestational diabetes mellitus, Logistic regression analysis showed that low AAO, low DTAA and high flow velocity at the stenosis site were risk factors of significant CoA (P<0.05). The results of ROC curves analysis showed that AUC values of AAO combined with DTAA and flow velocity at the stenosis site, and DTAA alone for predicting significant CoA were greater, showed good predictive value. Conclusion: Prenatal AAO, DTAA and flow velocity at the stenosis site have significant clinical predictive value in CoA. Among them, DTAA has the highest predictive value. In clinical practice, DTAA can be the first choice for prediction, while AAO and flow velocity at the stenosis site can be applied as auxiliary predictive indexes