Heavy Menstrual Bleeding Since Menarche in an 18-Year-Old: Most Likely Etiology
Von Willebrand disease (VWD) is the most likely cause of prolonged heavy menorrhagia since menarche in this 18-year-old with no other systemic findings, as it is the most common inherited bleeding disorder affecting up to 1% of the population and presents with heavy menstrual bleeding in 32-100% of affected women. 1
Primary Diagnostic Consideration: Von Willebrand Disease
VWD should be the leading diagnostic consideration when heavy menstrual bleeding has been present since menarche. 1, 2 The key clinical features that point toward VWD in this patient include:
- Menorrhagia present since menarche is highly predictive of an inherited bleeding disorder, occurring in 65% of VWD patients 3
- VWD is the most common inherited bleeding disorder, affecting males and females equally in approximately 1% of the population 1
- Heavy menstrual bleeding is the most common symptom women with VWD experience, with prevalence ranging from 32-100% 2
- The majority (90%) of adolescents with inherited bleeding disorders and menorrhagia experienced symptoms since menarche 4
Secondary Diagnostic Considerations
While VWD is most likely, other inherited bleeding disorders must be considered:
- Inherited bleeding disorders are found in approximately 17-20% of adolescents presenting with heavy menstrual bleeding 1, 5, 3
- Platelet function defects cause menorrhagia in 5-98% of affected women 2
- Factor XI deficiency presents with menorrhagia since menarche in 67% of cases 3
- Rare factor deficiencies (including Factor VII) cause menorrhagia in 35-70% of affected women 2, 3
Anovulatory Bleeding: Less Likely in This Case
Anovulatory cycles due to immature hypothalamic-pituitary-ovarian axis are the leading cause of heavy menstrual bleeding in adolescents overall 5, but several factors make this less likely as the primary etiology here:
- The 8-10 day duration suggests regular, albeit prolonged, cycles rather than the irregular bleeding typical of anovulation 6
- Menorrhagia present since menarche specifically predicts an inherited bleeding disorder rather than anovulation 3
- Anovulatory bleeding typically presents with irregular, unpredictable bleeding patterns 7
Critical Diagnostic Workup Required
Laboratory testing should be performed during menstrual bleeding to capture the lowest levels of VWF:Ag and FVIII:C 2. The essential initial screening includes:
- Complete blood count with platelets, prothrombin time, and activated partial thromboplastin time 6
- Factor VIII level, von Willebrand factor antigen, and ristocetin cofactor activity 8
- Pregnancy test, thyroid-stimulating hormone, and prolactin levels 7, 6
- Iron profile to assess for iron deficiency anemia from chronic blood loss 8
A pictorial blood assessment chart (PBAC) score ≥100 has >80% sensitivity and specificity for diagnosing menorrhagia (>80 mL blood loss) and increases diagnostic sensitivity to 95% when combined with history 2, 3.
Important Clinical Pitfalls to Avoid
- Do not perform invasive gynecologic procedures (hysteroscopy, endometrial ablation, hysterectomy) before excluding bleeding disorders, as these carry high postoperative bleeding risk in undiagnosed patients 3, 8
- Failure to test during menstruation may miss the diagnosis, as VWF levels fluctuate and are lowest during menses 2
- Do not attribute prolonged heavy bleeding solely to anovulation in adolescents without first excluding inherited bleeding disorders 5
- Assess for hypermobility disorders, as connective tissue disorders can present with bleeding symptoms and should be excluded 1
Quality of Life Impact
Menorrhagia in adolescents with bleeding disorders severely impacts quality of life and can present acutely with severe anemia requiring hospitalization (12% in one series) 4. This underscores the importance of prompt diagnosis and appropriate management rather than attributing symptoms to "normal adolescent irregularity."