Summary
In recent years, prothrombotic states have been not only associated with an increased
risk of venous thrombosis, but also with pregnancy complications. In particular there
is good evidence linking antiphospholipid antibody syndrome, which is associated with
increased thrombin generation (1), to recurrent miscarriage. The importance of procoagulant
changes in the pathophysiology of recurrent miscarriage is emphasised by the fact
that treatment with heparin and low dose aspirin will substantially improve the likelihood
of a successful pregnancy (2). Essentially, this is the only successful medical intervention
in the treatment of miscarriage. There are also data now accumulating that link congenital
thrombophilia to pregnancy complications such as miscarriage, pre-eclampsia, intra-uterine
growth restriction, abruption and intrauterine death (3, 4). Furthermore, recent data
have shown that acquired changes in the coagulation system, such as the acquired activated
protein C resistance of pregnancy is also associated with an increased risk of pre-eclampsia
(5). These data collectively suggest that procoagulant changes in general, rather
than congenital or acquired thrombophilia in particular are associated with the development
of pregnancy complications including fetal loss. However, in the majority of cases
of fetal loss no cause is found and we cannot easily link these events to a procoagulant
problem in the mother. In this issue of the Thrombosis and Haemostasis, Laude et al.
(6) report, for the first time, the association between circulating procoagulant microparticles
and pregnancy loss so providing a new insight into potential mechanisms.
