Efficacy of combined low-molecular-weight heparin and low-dose aspirin therapy versus aspirin alone in women with thrombophilia-related recurrent pregnancy loss: A retrospective cohort study.

The role of inherited thrombophilia (IT) in recurrent pregnancy loss (RPL) remains uncertain, unlike established antiphospholipid antibodies (APA). This study evaluated pregnancy outcomes in APA and IT patients, comparing low-molecular-weight heparin (LMWH) plus low-dose aspirin (LDA) versus LDA alone in IT. After excluding genetic, anatomical, and endocrinologic causes, 227 women with RPL related to APA or IT such as protein C, protein S, and antithrombin III deficiencies, factor V Leiden, or prothrombin gene mutations were enrolled. All women with thrombotic causes were taking LDA before pregnancy. LMWH was added after a positive pregnancy test in women with APA, and women with IT received either LMWH plus LDA or LDA alone. Pregnancy outcomes and miscarriage rates were compared by etiology and treatment. The APA group had significantly higher miscarriage rates than IT group (30.4% vs. 14.8%, p = 0.024) despite LMWH + LDA treatment. Within the IT group (106 LDA-only, 54 LMWH+LDA), miscarriage and full-term birth rates were similar, but early preterm birth < 34 weeks was significantly lower with LMWH + LDA treatment (p = 0.045). Women with APA-related RPL had worse outcomes than IT patients despite LMWH and LDA treatment. In IT-associated RPL, adding LMWH to LDA may not prevent miscarriage but could reduce early preterm birth risk.