Early Versus Late Post Cesarean Section Warfarin Initiation and Increased Risk of Maternal Complications in Patients With Mechanical Heart Valves: A Randomized, Open-Label Pilot Study.

Background and objectives: The timing of the reinstitution of warfarin after cesarean section (CS) delivery was not adequately addressed in the literature. This study aims to evaluate the risks of early versus late initiation of warfarin post-CS in patients with mechanical heart valves.

Methods: This randomized, open-label cohort study included 114 pregnant women with mechanical heart valves planned to be delivered by CS at or after 28 weeks of gestation. Patients were randomly divided into two groups: Day-2-group, where warfarin was started on day 2, and Day-5-group, where warfarin was started on day 5 after CS. Maternal postoperative bleeding complications, mechanical valve thrombosis, need for blood transfusion or reoperation, and maternal mortality were identified.

Results: Ten women (8.8%) had 11 bleeding complications, of whom 2 patients (20%) had intraperitoneal hemorrhage (none in Day-2-group and 2 in Day-5-group), 3 patients (30%) had subcutaneous hematoma (none in Day-2-group and 3 in Day-5-group), and 6 patients (60%) had sub-rectus hematoma (3 in Day-2-group and 3 in Day-5-group). No mechanical valve thrombosis, other thromboembolic events, or in-hospital maternal mortality were reported.

Conclusion: Despite the small number of events, the bleeding risk was lower in the group with early post-CS warfarin introduction than in the group with late warfarin introduction in patients with prosthetic heart valves.

Trial registration: ClinicalTrials.gov Identifier: NCT04855110.