Thrombin generation assays for optimizing low molecular weight heparin dosing in pregnant women at risk of thrombosis – response to Ismail et al

Abstract

We thank Ismail et al for their interest in our study (Chowdary et al, 2015) and for raising some important issues on this controversial topic. We acknowledge the limitation in our study: that this was a real life exercise and hence, the relatively wide time frame between low molecular weight heparin (LMWH) injection and blood sampling. Ismail et al reported typical anti-Xa pharmacodynamic profiles after fixed dose Tinzaparin in patients post-Caesarean section. However this is not really comparing like with like, because these are postpartum patients and observations post-surgical procedure are a study in themselves. It is interesting to note that Ismail et al reported very low peak anti-Xa levels with a concomitant reduction of thrombin-antithrombin (TAT). It would be interesting to see TAT levels in patients with a contraindication for LMWH as a control.