SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
Fetal aortic diameter
Aortic diameter is predicted from the following regression equation ((Y = 0.00912*X +
12.46) where Y = predicted aortic diameter, X = the pregnant mare's weight in pounds
and * = multiplied by).
Aortic root
A fetal aortic diameter with a standard error (5.038) 4 times larger or smaller than
predicted is abnormal. Fetal aortic diameters of < 18.5 mm in a late term fetus are
indicative of intrauterine growth retardation or twins.
Fetal thoracic diameter
The fetal thoracic diameter (ideally measured from withers to girth if possible) is also an
indicator of fetal size but there is more variability in the measure of fetal size due to the
inability to control fetal position.
164