Obstetric Implications of Activated Protein C Resistance and Factor V Leiden Mutation

An increasing number of reports have focused on activated protein C resistance (APCR) as it has been shown not only to be the most common genetic factor predisposing patients to thromboembolic disease but the most common identifiable cause overall. More than 90 percent of the cases of APCR are caused by the factor V Leiden mutation, in which a guanine to adenine substitution in the factor V gene at nucleotide position 1691 results in a glutamine to arginine switch at position 506. Recent studies have also pointed to evidence of an association between APCR/factor V Leiden mutation and hypertensive disorders of pregnancy, first and second trimester miscarriage, placental infarction, and placental abruption. Target Audience: Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to estimate the incidence of activated protein C resistance in the general population, to explain the pathophysiology of this condition, and to describe the controversies surrounding the management of this condition in pregnancy.