The Significance of Ductal Tortuosity in Late Gestation Fetuses with Normal Hearts -Is There a Relation to Ductal Flow Changes or Right Ventricular Functional Findings?

OBJECTIVE: To investigate whether tortuous ductus arteriosus (DA) is associated with changes in ductal Doppler flow or right ventricular (RV) functional findings in late-gestation, structurally normal heart fetuses. METHOD: Fetuses ≥ 32 weeks' gestation with tortuous DA from 01/2016 to 11/2023 were evaluated. Using the narrowest ductal angle and number of ductal bends, DA tortuosity grade was assigned as mild (one bend, ≥ 90 degrees), moderate (one bend, < 90 degrees), and severe (≥2 bends). DA flow included peak systolic flow velocity (PSV) and pulsatility index (PI). RV functional markers included tricuspid regurgitation, RV to left ventricle (LV) (RV/LV) size ratio, RV function and venous Dopplers. RESULTS: Eighty fetal echocardiograms were evaluated. The mean gestational age (GA) was 34.9 weeks. The majority of our cohort had either moderate tortuosity (47.5%) or mild tortuosity (40%) grade. The mean PSV was 1.6 m/s and 45% of subjects had elevated PSV for GA. The mean PI was 2.4, with 95% of our cohort having a normal or high PI for GA. DA tortuosity was not associated with DA PSV or PI for GA. Compared to the group with mild tortuosity grade, the moderate group had significantly higher mean RV/LV size ratio and lower mean narrowest ductal tortuosity angle. CONCLUSION: Variable ductal tortuosity is seen in late gestation fetuses with normal cardiac anatomy. The majority of our cohort had elevated PSV for GA but with a normal or high PI for GA. The degree of ductal tortuosity was not associated with PSV or significant RV functional changes.