Prospective comparison of the incidence of heavy menstrual bleeding (HMB) in women of reproductive age treated with direct oral anticoagulants (DOACs)

Patients will be treated as standard of care, no randomization schedule, no blinded investigational product (IP).

The decision which DOAC will be given is made before the subject will enter the trial. The DOAC has to be taken at least for seven days.

The registry is non-interventional (NIS) with routine blood draw at baseline and at month 4 after inclusion. The prospective follow up will be up to four months. Three consecutive menstrual bleeding cycles will be documented by the participating patients at home. One baseline data reporting and one follow up reporting after four months are planned in the participating coagulation centers.

The primary aim is the comparison of the frequency of heavy menstrual bleeding in female patients of reproductive age anticoagulated with DOACs using a modified pictorial blood loss assessment chart.

Secondary aims are the prevalence of von Willebrand disease in young anticoagulated female patients and correlation of HMB with age, International Society of Thrombosis and Hemostasis bleeding assessment tool at inclusion, Blood group, anatomical reasons i.e. underlying uterine pathologies, i. e. presence of uterine fibroids, endometrial polyps and/or adenomyosis, occurrence of iron deficiency, hemoglobin level and intermittent use of non-steroidal anti-inflammatory drug (NSAID).

Inclusion Criteria:

• Women with venous thromboembolism
• Age: 18 - 50 years
• Regular menstrual bleeding
• Treatment with DOACs for at least 7 days before inclusion
• Full therapeutic anticoagulation with rivaroxaban 1 x 20 mg, apixaban 2 x 5 mg, edoxaban 60mg once daily or dabigatran 2 x 150mg for at least the next four months
• Written informed consent

Exclusion Criteria:

• Hysterectomy or ovariectomy
• Known heavy menstrual bleeding
• Hormonal contraceptives
• Hormone replacement therapy
• Use of hormone releasing intrauterine System (IUS)
• Contraindications to treatment with DOACs
• Treatment with rivaroxaban 15 mg twice daily (first three weeks after diagnosis of venous thrombosis) or apixaban 10 mg twice daily (first week after diagnosis of venous thrombosis)
• Treatment with rivaroxaban (10 mg or 15 mg once daily) or apixaban (2,5 mg twice daily) in reduced therapeutic dosages
• Participation in any other trial

Expected number of patients estimated by study duration n=150 patients treated with direct oral anticoagulants (DOAC) due to venous thromboembolism.