[Pregnancy and venous thromboembolism. North-American and European guidelines. American College of Chest Physicians].

Guidelines concerning the prevention and treatment of pregnancy-associated venous thromboembolism (VTE) have been elaborated by the American College of Chest Physicians and published in Chest in 2008. In this review, they have been compared with European guidelines and discussed taking into account the papers published since 2008.Most recommendations are of low grade of evidence because randomized studies are lacking during pregnancy and many reflect guidelines proposed by experts. The decisions on the most appropriate prophylaxis, dose to be administered and moment of pregnancy for starting prophylaxis are often decided case by case after careful assessment of the risk of pregnancy-associated VTE, on one hand, and the risk for the mother, on the other.Risk factors (age >or= 35, obesity, history of VTE with or without sequellae, in vitro fertilization)or thrombophilia have to be taken into account. Scores have been proposed to improve standardisation and evaluation of the risk of VTE and they should be validated.