Understanding the problem

When individuals have recurrent miscarriages, they may have their blood tested for inherited blood clotting disorders (e.g., Factor V Leiden mutation, Prothrombin gene mutation, Antithrombin deficiency, Protein C deficiency, Protein S deficiency). It is believed that these clotting disorders may cause tiny blood clots to form in the placenta that can lead to miscarriage. If a clotting disorder is diagnosed, they may be prescribed low-molecular weight heparin (LMWH) injections to give to themselves during their next pregnancy. The hope is that these injections will prevent the tiny blood clots and reduce the risk of miscarriage. However, there has been little research to prove this treatment works.

The researchers in this study wanted to know if LMWH injections started during attempts to conceive or early confirmed pregnancy would reduce the risk of miscarriage and increase the likelihood of individuals diagnosed with inherited blood clotting disorders having a livebirth.