F5 and placental abruption: There was no significant association between factor V Leiden and prothrombin gene and the composite outcomes of pre-eclampsia, small for gestational age (SGA), pregnancy loss or placental abruption with pooled odds ratios of 1.08 (95% CI 0.87–1.52) and 1.27 (95% CI 0.94–1.71), respectively.