Table 5  Comparison of recommendations in the most recent German, American and British guidelines on RSA (< 20th week of pregnancy) and maternal thrombophilia without prior VTE.

RSA without VTE	German guideline 37	American guideline 38	British guideline 39
RSA: recurrent spontaneous abortion; VTE: venous thromboembolism; LA: lupus anticoagulant; AT activity: antithrombin activity; APC resistance: anti-protein C resistance; FVL: factor V Leiden mutation; PGM: prothrombin gene (G20210A) mutation; APS: antiphospholipid syndrome; LMWH: low molecular weight heparin
Screening for APS (LA, anticardiolipin antibodies IgG and IgM, anti-β2 GP1 antibodies IgG and IgM)	Yes	Yes (level of evidence 1B)	Yes (level of evidence D)
Screening for hereditary thrombophilia	AT activity, APC resistance/FVL, PGM	No (level of evidence 2C)	Only if the reason for pregnancy loss from the 2nd trimester is unclear: FVL, PGM, protein S deficiency (level of evidence D)
Prophylactic administration of medication
Hereditary thrombophilia	No administration outside clinical studies	No (level of evidence 2C)	LMWH for pregnancy losses from the 2nd trimester (level of evidence A)
APS	Low-dose ASA and LMWH	Low-dose ASA and LMWH (level of evidence 1B)	Low-dose ASA and LMWH (level of evidence B)