Bleeding Complications Associated With Intrauterine Contraception in Women Receiving Anticoagulation Therapy

OBJECTIVE: To determine whether anticoagulation therapy is associated with an increased risk of complications after initiation of intrauterine contraception (IUC). PATIENTS AND METHODS: We retrospectively reviewed records of women receiving anticoagulation therapy at the time of IUC placement from 2000 to 2017 and records of controls (no anticoagulation), matched by race, age, and body mass index. The primary outcome was the cumulative incidence of bleeding (more than spotting [World Health Organization bleeding grades 2 to 4]), IUC expulsion, and IUC removal. Secondary outcomes included treatment for bleeding and bleeding patterns stratified by medication and IUC type. Outcomes were assessed at 24 hours, 30 days, and 6 months after IUC placement. RESULTS: We matched 208 women taking anticoagulants with 421 controls. The most common anti-coagulant agents were aspirin (60.1%) and warfarin (36.1%). Most women received the levonorgestrel IUC. No complications occurred within 24 hours. Patients receiving anticoagulants had higher rates of the primary composite outcome at 30 days (odds ratio, 1.77 [95% CI, 1.04 to 3.04]; P=.04) and at 6 months (odds ratio, 2.05 [95% CI, 1.29 to 3.26]; P=.002). Primary complications did not differ by IUC type among control patients, but among women receiving anticoagulants, nonhormonal IUC was associated with an increased rate of complications (P=.04). CONCLUSION: Anticoagulation therapy was associated with higher rates of bleeding at 30 days and 6 months, and nonhormonal IUC plus anticoagulation therapy was associated with higher rates of primary complications. Our findings support current periprocedural anticoagulation guidelines, which state that anticoagulation and antiplatelet therapy can be continued at the time of IUC insertion.