Tissue factor and tissue factor pathway inhibitor in women with a past history of preeclampsia: implication for a hypercoagulable state postpregnancy

Preeclampsia (P-EC) is a multisystem disorder of pregnancy whose cause and pathogenesis remain poorly understood. However, abnormal haemostasis and endothelial dysfunction are thought to be implicated. Women with a past medical history of P-EC have a baseline hypercoagulable state postpregnancy. The aim of this study is to examine the relationship between tissue factor (TF) and TF pathway inhibitor (TFPI) in women who have had P-EC within the last 3 years (more than 6 months postpartum) and their normal counterparts. Blood specimens were collected from women known to have had P-EC within the last 3 years (n = 26) and aged-matched healthy women without past history of P-EC in previous pregnancy (n = 26). Plasma TF and TFPI levels were measured using ELISAs. Women who have had P-EC showed increased TF levels compared with their normal counterparts, whereas TFPI levels were reduced. Neither parameter differed significantly when the groups were tested against each other. Interestingly, the TF/TFPI ratio was significantly increased (P = 0.024) when the two groups were compared. In summary, there was a trend towards increased TF and reduced TFPI levels in the P-EC group. Such a tendency was not statistically significant. However, the TF/TFPI ratio was significantly increased when the groups were compared. Our findings suggest an imbalance between TF/TFPI levels in women with past history of P-EC postpregnancy. This may contribute to the development of maternal hypercoagulable states and may predispose women with a history of P-EC to cardiovascular risks later in life.