Introduction of a new fetal examination protocol for on-field and clinical equine practice

Abstract

Prepartum fetal surveillance techniques have been widely used in both human and veterinary obstetrics, although these tests differ in their sensitivity for the assessment of fetal well-being. In equine reproduction, the ‘gold standard’ examination technique is the equine biophysical profile (EBP) described by Virginia Reef in 1995. Although this fetal assessment has many benefits, its accuracy, sensitivity and specificity have not been evaluated so far. In this study, 129 late-term pregnant mares were scanned twice in their last month of gestation using two different protocols (the EBP and a new, rapid examination protocol, REP) in order to determine the accuracy of these tests. The REP included the determination of fetal heart rate, fetal aortic diameter and the combined thickness of the uteroplacental unit. Twenty-seven fetuses proved to be compromised and 102 mares had healthy asymptomatic foals. Statistical analyses showed slight differences in test sensitivity (81.48% and 85.19%), specificity (83.3% and 87.25%) and accuracy (82.95% and 86.82%) for EBP and REP, respectively. Furthermore, a statistically significant interchangeability could be demonstrated between the two methods. It is concluded that, depending on the prevalence of the disease (here: compromised state), both methods are useful for the diagnosis of fetal abnormalities and make it possible to provide satisfactory care for broodmares and their fetuses.