| dc.description.abstract | Contrary to its widespread use in human cases, the use of Doppler ultrasonography is only recently becoming
prevalent in farm animals. This study aimed to determine the effects of maternal metabolic and clinical changes
on fetal hemodynamics during pregnancy toxemia with the doppler examination of umbilical cord. In the study
twenty ewes with a single healthy fetus were included in the study. At the end of the 120th day of pregnancy, 20
single-bearing pregnant ewes were randomly categorized into two groups. Ewes in the control group were fed to
meet all nutritional requirements. On the other contrary, the experimental ewes were fed to meet equivalent to
50 % of the daily needs and then fasted for 96 h. Doppler ultrasonographic examinations of umbilical cord were
performed once every two days and once a day during fasting. Beta hydroxybutyric acid (BHBA) concentration
was measured by taking blood from sheep on examination days. Pulse systolic velocity (PSV), end diastolic
velocity (EDV), PSV/EDV, pulsatility index (PI), resistance index (RI), and fetal heart rate (FHR) as well as BHBA
values and how those parameters has changed over time (time by treatment effect) due to energy deprivation
during pregnancy were evaluated using repeated measure analysis of variance. No clinical signs were observed in
both toxemia and control groups during restricted feeding. BHBA concentration increased and there was a significant time, time by treatment and main effect of treatment effect between groups. No significant main effect of
treatment and time by treatment interaction was observed in the changes of PI, RI, FHR, and systolic/diastolic
velocity values over time in both groups. FHR was reduced over time, and there was a significant time effect in
FHR in both groups. Although doppler indices didn't increase, both PSV and EDV values increased significantly in
the pregnancy toxemia group compared with the controls (Time P = 0.03, time by treatment interaction P <
0.05) and the main effect of treatment P < 0.05). The marked increase in blood velocities (PSV and EDV) in the
umbilical cord is probably due to the compensatory functioning for excessive energy deprivation of the fetus.
Therefore, PSV and EDV might be a valuable indicator for evaluating the fetus's health status during the management of the PT. | tr |
