Background Pregnancy complications such as pre‐eclampsia and eclampsia, intrauterine
growth restriction and placental abruption are thought to have a common origin related to
abnormalities in the development and function of the placenta. Objectives To compare,
using the best available evidence, the benefits and harms of antenatal antithrombotic
therapy to improve maternal or infant health outcomes in women considered at risk of
placental dysfunction, when compared with other treatments, placebo or no treatment.