Inclusion Criteria:  >18 ages Who had given birth at Centre Hospitalier Sud Francilien Hospitalized during the puerperium at Centre Hospitalier Sud Francilien Being informed of the clinical trial and had offered any opposition for data collection  Exclusion Criteria:  Curative treatment of thrombosis by Low molecular-weight or unfractioned heparin during pregnancy or post-partum period Curative anticoagulant therapy for any cause