Potential Association Between Placental Features And Apgar Scores After Normal Parturition In The Thoroughbred Horse

Recently, the important role of the placenta in the well-being of the equine newborn has received more attention. It is well known that placenta efficiency mirrors the feto-maternal gas and nutritional exchanging. In the last years the APGAR score system has been proposed to assess the degree of peripartum asphyxia in foals. The aim of the present study was the assessment of potential association between placental features and APGAR scores after normal parturition in the Thoroughbred horse. Twenty-nine normal Thoroughbred foalings were observed and historical data concerning the mares were recorded. Each foal was assessed by the APGAR test within 20 minutes from birth and classified into one of the four classes of asphyxia. Before suckling each foal was weighed on an equine weight scale. Within 1 hour of fetal membrane shedding, the placentae were classified grossly, depending on the presence of the lesions. Placenta samples were collected for histological examination. The results showed that a better APGAR class was positively correlated (p<0.05) to longer pregnancies and that the best APGAR class of foals was positively related to the placentae belonging to the best gross (p<0.0001) and histological class (p<0.01). A positive high correlation (p<0.0001) between gestational length and foal birthweight was also found, while no significant correlations between foal birthweight and both gross and histological classification were observed. In conclusion, the finding that foal APGAR class can be influenced by even mild abnormalities, underlines the importance of histological examination of placentae during the routine postpartum management of the mare and newborn.