Prothrombotic risk factors in the evaluation and management of perinatal stroke.

The ischemia in children affected by perinatal stroke has long been thought to be driven by nonhematologic maternal and perinatal events. New information from clinical studies, however, tells us that plasma-phase risk factors, such as factor V Leiden, elevated lipoprotein (a), and mutations in MTHFR, may be important in the pathogenesis of perinatal stroke, if not always in the risk of recurrence. With regard to stroke recurrence, this risk is only about 2% according to the largest follow-up study to date, and certainly less than 5%. Nonetheless, when strokes do recur, they tend to be associated with the presence of plasma-phase risk factors in the affected child, suggesting that a small percentage of children with a first perinatal stroke may benefit from anticoagulation therapy, both to prevent stroke recurrence as well as occurence of a second, non-CNS thrombotic event. Counselling of parents with regard to subsequent pregnancies should always include medical management of systemic maternal disorders, such as diabetes, persistently elevated antiphospholipid antibodies, and inherited maternal hypercoagulability states.