چکیده (انگلیسی):

Objective: The study was designed to estimate the relationship between gestational age
and transabdominal ultrasonographic measurements of fetus and uterus during the 2nd
and 3rd trimester of gestation in cows.
Methods: Seventeen cows with confirmed conception dates were used. The cows were
examined transabdominally in standing position using the 3.5MHz convex sector transducer
of real-time ultrasonography. Measurements of length and height of placentomes, distance
between uterine walls, width of trunk and heart, intercostal distance and width of umbilical
cord were obtained from the ultrasonographic images by using the screen caliper software.
Results: Measurements at <90 and >250 d of gestation were for placentomes length
(17.87 ± 2.26) and (75.92 ± 7.76) mm, height of placentomes (13.37 ± 1.12) and
(36.50 ± 3.92) mm, distance between uterine walls (71.45 ± 10.68) and (144.63 ± 7.29)
mm, and width of umbilical cord (7.80 ± 0.42) and (16.41 ± 0.41) mm, width of trunk
(35.67 ± 7.11) and (146.50 ± 5.34) mm, width of heart (15.10 ± 5.50) and (74.57 ± 4.20)
mm, and intercostal distance (3.85 ± 0.49) and (21.79 ± 0.48) mm, respectively. All the
measurements were highly significantly correlated with gestational age (P < 0.01). The
measurements showing the highest correlation with gestational age were the width of
heart (r = 0.977), width of trunk (r = 0.965), and intercostal distance (r = 0.952), while the
remaining measurements shown the least correlation with gestational age; distance between
uterine walls (r = 0.887), width of umbilical cord (r = 0.882), placentomes length
(r = 0.880), and placentomes height (r = 0.788).
Conclusion: Transabdominal ultrasonography is a practical and reliable method for
obtaining the fetal and uterine measurements during the 2nd and 3rd trimesters of gestation.
The correlation coefficients between gestational age and fetal measurements (width of trunk
and heart and intercostal distance) were higher than those of uterine measurements, and the
highest correlation was between heart width and gestational age in cows.