Objective: Twin pregnancies are accompanied by various perinatal complications. The study of placentae is important for understanding the underlying pathogenesis and pathologies. Annexin A5 (ANXA5) is an anti-thrombotic agent, which is expressed by the placental trophoblasts. Apelin is a novel adipokine with a significant role in angiogenesis of the placenta. The aim of the present study was to compare the gross, histopathological findings and immunohistochemical expression of ANXA5 and apelin of twin placentae with those of matched controls. These findings were also correlated with the clinical features of both mother and neonate.

Material and Methods: A prospective, observational study was undertaken for a span of one year. Twin placentae were collected along with their matched controls. The gross and microscopic features, as well as immunohistochemical expression of ANXA5 and apelin in these placentae were noted.

Results: There was a significantly lower expression of ANXA5 and apelin in the 24 twin placentae collected when compared with matched controls. The histopathological features of twin placentae included villous infarction (8, 33%), fibrin deposition (24, 100%), chorangiosis (18, 75%), and intraplacental hematoma (18, 75%).

Conclusion: Both ANXA5 and apelin are vital for placental homeostasis. The reduction in expression of these markers in twin pregnancies indicates their contribution to adverse outcomes of these cases. Studies with larger sample size are required in the future for further exploration of the role of these novel markers.