Ovine placenta related to binucleated cells in fetal membrane retention

Abstract

Placentomes were collected from 28 Iraqi Awassi ewes which had retained their fetal membranes after; (a) normal birth ( n = 6); (b) abortion ( n = 6), (c) dystocia ( n = 10), and (d) Caesarean section ( n = 6). Histologic changes in placentomes obtained from ewes with retained fetal membranes (RFM) after normal birth included vascular changes (edema, hyperemia and hemorrhages), hemosiderin pigmentation, necrosis in the maternal villi and presence of moderate to large numbers of binucleate cells (BNC). In placentomes obtained from ewes having RFM after abortion, there were vascular changes in both maternal and fetal connective tissues. Necrosis and massive bacterial colonies were seen in the caruncles and cotyledons. Few numbers of BNC and infiltration of polymorphonuclear and mononuclear cells in the caruncles and cotyledons were observed. The changes in placentomes obtained from ewes having RFM after dystocia (treated by assisted delivery) included the presence of vascular changes, hemosiderin pigmentation, moderate degree of necrosis and few bacterial colonies in the caruncles and cotyledons. Moderate numbers of BNC were observed. On the other hand, in cases of dystocia (treated with a Caesarean section), vascular changes, moderate degrees of necrosis and few numbers of bacterial colonies were observed in caruncles and cotyledons and only few BNC. It was concluded that BNC are involved in the process of placental separation in ewes.