Anticoagulant prophylaxis for placenta mediated pregnancy complications

Thrombophilias are not yet established as a cause of the placenta-mediated pregnancy complications (pregnancy loss, pre-eclampsia, small for gestational age and placental abruption). A thrombophilia may be only one of many factors that lead to development of these complications. Our recent large systematic review of prospective cohort studies highlight that the association between thrombophilia and placenta mediated pregnancy complications is far from proven. The small step of previously describing an association in case control studies has led a large number of clinicians and opinion leaders to take the large leap of accepting this relationship as being causal and potentially treatable with anticoagulant interventions. Furthermore, while data in women with prior severe pre-eclpamsia, abruption and small for gestational age births without thrombophilia suggests some promise for anticoagulant prophylaxis to prevent complications in subsequent pregnancies in these women, in the absence of large well done and generalisable "no intervention" controlled studies adopting anticoagulant prophylaxis to prevent these complications is premature. The absence of strong evidence, coupled with the small potential for harm from anticoagulant prophylaxis suggests that these drugs should be considered experimental in thrombophilic and non-thrombophilic women with prior placenta mediated pregnancy complications.