Table 2 Subpopulations of pregnant women recommended for LMWH prophylaxis or treatment

Which subpopulation(s) of pregnant women, ante- or post-partum, or those with recurrent pregnancy loss, should be treated with LMWHs such as enoxaparin?

• Women with recurrent pregnancy loss

• No evidence to support use of LMWH to prevent recurrent pregnancy loss

• Women with antiphospholipid syndrome or with heterozygosity of factor V Leiden mutation

• Those undergoing IVF

• Those with previous unprovoked or provoked VTE

• LMWH is recommended in the case of a severe event such as placenta abruption, intrauterine foetus death or VTE

• ACCP/CHEST [28]: For women requiring long-term VKA treatment who are attempting pregnancy, a switch to LMWH is recommended. In women with no VTE risk factors, prophylaxis is not recommended following a caesarean section. No routine prophylaxis for patients following assisted reproduction

• ASH [14]: Prophylaxis is only advised for women undergoing assisted reproductive therapy with severe ovarian hyperstimulation syndrome. For women with previous unprovoked or provoked VTE, ante-partum prophylaxis is advised. For women with antithrombin deficiency who are homozygous for the factor V Leiden regardless of family history, ante-partum and post-partum prophylaxis is recommended. In those with protein S or C deficiency, post-partum prophylaxis is advised

• Italian Society of Thrombosis and Haemostasis [29]: Ante- and post-partum prophylaxis is recommended for women with thrombophilic defects. LMWH is recommended in women with prior VTE. Ante- and post-partum LMWH prophylaxis is suggested for women with prior obstetric complications and one thrombophilic defect

• RCOG [13]: LMWH is the preferred anticoagulant to treat acute VTE and for antenatal and post-natal prophylaxis. 10 days prophylaxis with LMWH is recommended after an emergency caesarean section and after a planned caesarean section if there are additional risk factors