Changes in Doppler Ultrasonography and Echotexture Parameters in Cows During the Last 10 Days of Pregnancy.

Objectives: This study aimed to investigate changes in Doppler sonographic measurements of uterine artery blood flow to the placenta, as well as variations in placentome echotexture/perfusion and myometrial thickness in cows during the last 10 days of pregnancy.

Methods: The study utilized eight pregnant Brown Swiss cows. In assessing the echotexture of the placentome and myometrium, the mean grey value (MGV) was measured, along with the placentome area and myometrium thickness (MT). For placentome perfusion analysis and spectral analysis of the uterine artery, parameters, including pulse rate (PR), resistance index (RI), blood flow velocity (BFVe), blood flow volume (BFVo) and diameter (DM), were recorded.

Results: During the last 10 days of pregnancy, the placentome area and MT exhibited a declining trend from the start of sampling until delivery (p = 0.005). Both placentome and myometrium MGV showed an increasing trend over the study period (p < 0.001). Placentome perfusion decreased significantly 3 days prior to delivery (p < 0.05). A significant difference was observed in BFVe/DM in the uterine arteries between pregnant and non-pregnant horns. RI (p = 0.005) and PR (p = 0.009) values changed significantly over time.

Conclusions: As a result, differences in ultrasonographic findings were observed during the last 10 days of pregnancy in cows. It can be concluded that changes, particularly in the final 2 days, may be associated with placental maturation mechanisms.