Thromboelastometry as an Ancillary Tool for Evaluation of Coagulation Status after rFVIIa Therapy in a Pregnant Woman with Severe Hypoproconvertinemia-A Case Series and Review of the Literature.

Factor VII (FVII) deficiency is a rare hemorrhagic diathesis. In females, heavy menstrual and postpartum bleeding can appear as a consequence of its deficiency. Supplementation of the recombinant FVIIa is widely accepted. The supplementation effect in FVII-deficient subjects is difficult to predict, and severe hemorrhage has been described even when FVII levels after supplementation were within normal ranges. The aim of this report is to present the application of thromboelastometry to control the coagulation status in a patient with severe FVII deficiency during pregnancy and delivery, supplemented by rFVIIa per protocol complicated with life-threatening venous thromboembolism. Rotational thromboelastometry (ROTEM) was performed in 16 pregnant women: in one 28 year old primigravida at 35 weeks of pregnancy with congenital FVII deficiency after rFVIIa administration and 15 healthy women at 38 gestational weeks. The results were compared. The thromboelastometry results showed significant shortening of the clotting time in the extrinsic and the intrinsic pathway in the hypoproconvertinemia patient after rFVIIa administration in relation to healthy pregnant women. A significant reduction in maximum lysis of the clot after FVII supplementation was observed. The thromboelastometry results showed a significant hypercoagulable state with hypoproconvertinemia. Thrombotic complications after delivery might be prevented by the reduction in rFVIIa guided by thromboelastometry. Thromboelastometry performed on a pregnant woman with factor VII deficiency during the supplementation of rFVIIa in peripartum time might be helpful in order to determine an individual, effective dosage regimen of rFVIIa to ensure full correction of clotting disorders without the tendency to develop thrombosis, but further studies are needed.