Normal Doppler Reference Values of the Pericallosal Artery

Purpose: To provide the normal reference values of the Doppler flow of the pericallosal artery in relation to gestational age from 18 to 41 weeks of gestation. Materials and Methods: The pericallosal artery (PCA) was studied in 466 normal pregnancies. The pulsed Doppler evaluation of the pericallosal artery was done in A3 and A4 segments, and records from PI, RI and Vmax were studied. Results: The resistance index of the pericallosal artery in A3 / A4 segments exhibits a plateau from 18 to 31 weeks of gestation. After 31 weeks, a marked decrease becomes apparent. The pulsatility index of the pericallosal artery in A3 / A4 segments shows a plateau until 36 weeks of gestation. During the final weeks of gestation, there is a decrease in the pulsatility index. Vmax exhibits a plateau for the maximal flow velocity in A3 / A4 segments of the pericallosal artery from 18 to 28 weeks of gestation. After 28 weeks of gestation, there is a slight increase in Vmax. Conclusion: Normal reference values of the pericallosal artery might have an impact on clinical judgment during adaptive hemodynamic changes and regarding the progression of the fetal deterioration occurring in the presence of fetal hypoxia.