Annexin A5/ANXA5 is a multifunctional protein that is highly expressed on the apical surfaces of syncytiotrophoblasts, and plays an important role in haemostatic regulations, maintaining blood fluidity of the placenta. Annexin A5 (ANXA5) is a protein abundantly expressed in normal placenta where it contributes to the healthy outcome of a pregnancy. The association found between the maternal carriage of the M2/ANXA5 haplotype and an elevated risk of IUGR and/or PE supports the hypothesis that carrier status of this haplotype and the consequently reduced placental ANXA5 expression might be responsible, at least partially, for the onset of these gestational vascular complications. ANXA5 could be used as a biomarker for the early detection of PE and for the prediction of its severity. ANXA5 as an embryonic anticoagulant that appears deficient in contiguous specter of thrombophilia-related pregnancy complications culminating more frequently in miscarriage in a maternal M2 carrier background. As a potential indicator for malignancy and lymphatic metastasis, ANXA5 overexpression increases in vitro migration and invasion of Hca-P cell, promotes in vivo malignancy, LNM rate and level of Hca-P-transplanted mice. Hereditary thrombophilias can impair vascular placental functions and predispose to the birth of small-for-gestational age (SGA) babies. The placental anticoagulant protein annexin A5 (ANXA5) may contribute to this process.
