The adverse reactions reported by the investigator as at least possibly related to fondaparinux are presented within each frequency grouping (very common ≥ 1/ 10; common: ≥ 1/ 100 to < 1/ 10; uncommon: ≥ 1/ 1,000 to < 1/ 100; rare: ≥ 1/ 10,000 to < 1/ 1,000; very rare < 1/ 10,000) and system organ class by decreasing order of seriousness; these adverse reactions should be interpreted within the surgical and medical context.