Thrombelastometric results and platelet function during pregnancy in women receiving low molecular weight heparin with a history of recurrent/late abortion – A retrospective analysis

In women with a history of recurrent/late abortion and confirmed genetic/acquired thrombophilia, LMWH was given during subsequent pregnancy and serial coagulation testing was performed.

In 82 consecutive pregnant women with recurrent (≥2) and/or late abortion (>12 GW) in the presence of single (n = 62; 75.6%) or combined (n = 20; 24.4%) genetic and/or acquired thrombophilia, Thromboelastometry (n = 50; ROTEM, TEM) and closure-time (n = 82; PFA-100; Siemens) underwent serial testing before and during pregnancy while receiving LMWH and puerperal.

Throughout pregnancy, clotting-time (CT) after intrinsic and extrinsic induced coagulation activation in Thromboelastometry remained unchanged. TF-induced coagulation activation resulted in statistically significantly decreased mean clot-formation-times (CFT) (Trim I: 108.9 ± 5.2 S to Trim III; 81.7 ± 5.4 S; p = 0.001), whereas after contact activation (Intem-S: Trim I: 70.1 ± 4.0 S to Trim III: 65.4 ± 6.8; n.s.) CFT remained unchanged. Mean maximal-clot-firmness (MCF) continuously increased in the Intem-S and Extem-S during each trimester and decreased until 4th puerperal week (Extem-S: Trim I: 61.9 ± 1.0 S; Trim II: 65.4 ± 0.58 S; Trim III: 68.3 ± 1.1 S; p <  0.001; Intem-S: Trim I: 64.1 ± 0.6 S; Trim II: 66.8 ± 0.5 S; Trim III: 69.5 ± 1.2 S; p <  0.001). Mean Closure-times after Epinephrine/ADP/Collagen stimulation remained unchanged during pregnancy.

In women with different thrombophilia receiving LMWH at prophylactic dose a significant increase in MCF was accompanied by barely unchanged CT after intrinsic and extrinsic coagulation activation and platelet mediated closure-times in the course of the pregnancy. Decrease in CFT was only seen after extrinsic coagulation activation, whereas unchanged CFT after intrinsic coagulation activation may be the result of LMWH given at low dose.