Is fondaparinux safe for use during pregnancy? A state-of-the-art review of current evidence.

Fondaparinux, a synthetic pentasaccharide, represents the smallest heparin-based molecule and functions as a potent selective indirect inhibitor of activated factor Xa. Its high bioavailability, ease of dosing, and favorable tolerability profile render it an ideal antithrombotic agent for pregnant patients who are intolerant to unfractionated heparin (UFH) and low-molecular-weight heparins (LMWHs). Recent studies have highlighted the advancements in the use of fondaparinux in pregnant patients over the past decades. This research provides a comprehensive summary of the safety profiles of fondaparinux, noting that its application in pregnant women may elevate the risk of bleeding events during pregnancy and postpartum. Caution is advised when administering fondaparinux to patients with renal insufficiency. The advantages of fondaparinux include a lower risk of thrombocytopenia, liver injury, allergic reactions, and osteopenia compared with UFH and LMWHs. Although fondaparinux can cross the placental barrier and be detected in the umbilical-cord blood, real-world data have not established a direct association between fondaparinux and teratogenicity or adverse fetal outcomes. Overall, fondaparinux appears to be a viable option for certain groups of pregnant patients requiring anticoagulation. However, further research is warranted to provide deeper insights into the benefits and risks associated with fondaparinux use in this population. The long-term effects of intrauterine exposure to fondaparinux remain an important area for future investigation.