Abnormal inflammation leads to maternal coagulopathies associated with placental haemostatic alterations in a rat model of foetal loss.

Spontaneous pregnancy loss is often associated with aberrant maternal inflammation and systemic coagulopathies. However, the role of inflammation in the development of obstetric coagulopathies is poorly understood. Further, questions remain as to whether systemic coagulopathies are linked to placental haemostatic alterations, and whether these local alterations contribute to a negative foetal outcome. Using a model of spontaneous foetal loss in which pregnant rats are given a single injection of bacterial lipopolysaccharide (LPS), we characterised the systemic maternal coagulation status following LPS administration using thromboelastography (TEG), a global haemostatic assay that measures the kinetics of clot formation. Systemic maternal coagulopathy was evident in 82% of LPS-treated rats. Specifically, we observed stage-I, -II, and -III disseminated intravascular coagulation (DIC) and hypercoagulability. Modulation of inflammation through inhibition of tumour necrosis factor α with etanercept resulted in a 62% reduction in the proportion of rats exhibiting coagulopathy. Moreover, inflammation-induced systemic coagulopathies were associated with placental haemostatic alterations, which included increased intravascular, decidual, and labyrinth fibrin deposition in cases of DIC-I and hypercoagulability, and an almost complete absence of fibrin deposition in cases of DIC-III. Furthermore, systemic and placental haemostatic alterations were associated with impaired utero-placental haemodynamics, and inhibition of these haemostatic alterations by etanercept was associated with maintenance of utero-placental haemodynamics. These findings indicate that modulation of maternal inflammation may be useful in the prevention of coagulopathies associated with complications of pregnancy.