Is thrombophilia associated with placenta‐mediated pregnancy complications? A prospective cohort study

Background Case control studies suggest that genetic thrombophilias increase the risk of placenta‐mediated pregnancy complications (pregnancy loss, small for gestational age (SGA), preeclampsia and/or placental abruption). Cohort studies have not supported this association but were underpowered to detect small effects. Objective To determine if factor V Leiden (FVL) or the prothrombin gene mutation (PGM) were associated with placenta‐mediated pregnancy complications. Patients/Methods A prospective cohort of unselected, consenting pregnant women at three Canadian tertiary care hospitals had blood drawn in the early second trimester and were genotyped for FVL and PGM after delivery. The main outcome measure was a composite of pregnancy loss, SGA