What is the most likely cause and recommended evaluation and treatment for iron‑deficiency anemia in a 38‑year‑old woman with heavy menstrual bleeding?

Iron Deficiency Anemia in a 38-Year-Old Woman with Heavy Menstrual Bleeding

Start oral ferrous sulfate 200 mg three times daily immediately to correct the anemia and replenish iron stores, while simultaneously addressing the heavy menstrual bleeding as the primary cause. 1, 2

Most Likely Cause

Heavy menstrual bleeding (menorrhagia) is the most common cause of iron deficiency anemia in premenopausal women, affecting 5-10% of menstruating women. 1 In a 38-year-old woman presenting with both conditions, the menorrhagia is almost certainly driving the iron deficiency. 3, 4

Immediate Iron Replacement Therapy

All patients with iron deficiency anemia require iron supplementation regardless of the underlying cause. 1, 2

• Prescribe ferrous sulfate 200 mg three times daily as first-line treatment due to its effectiveness and low cost, though ferrous gluconate and ferrous fumarate are equally effective alternatives. 1, 2

• Continue iron therapy for three months after hemoglobin normalizes to fully replenish body iron stores. 1, 2

• Expect hemoglobin to rise by 2 g/dL after 3-4 weeks of treatment; failure to achieve this suggests poor compliance, continued blood loss, malabsorption, or misdiagnosis. 1, 2

• Consider adding ascorbic acid if response is poor, as it enhances iron absorption. 1

• Reserve parenteral iron only for intolerance to at least two oral preparations or documented non-compliance, as it is painful, expensive, carries anaphylactic risk, and offers no faster hemoglobin rise than oral therapy. 1, 2

Diagnostic Evaluation

Screen for Coeliac Disease

• Obtain anti-endomysial antibody testing with IgA measurement (to exclude IgA deficiency which makes the test unreliable) in all patients under 45 years without upper GI symptoms. 1, 2

Quantify Menstrual Blood Loss

• Use pictorial blood loss assessment charts, which have 80% sensitivity and specificity for detecting menorrhagia, as patient history alone is unreliable for quantifying menstrual loss. 1, 2

Age-Stratified Investigation Approach

Since this patient is under 45 years old, the British Society of Gastroenterology guidelines recommend a more conservative approach:

• Perform upper GI endoscopy with small bowel biopsy only if upper GI symptoms are present. 1

• Perform colonoscopy only if specific indications exist (e.g., change in bowel habits, family history of colon cancer), as the incidence of significant pathology is lower in this age group. 1

• Patients over 45 years require full investigation with both upper endoscopy/small bowel biopsy and colonoscopy or barium enema. 1

Treatment of Heavy Menstrual Bleeding

Treating the underlying gynecological condition is essential to prevent ongoing iron loss. 2

Evidence-based options include:

• Levonorgestrel-releasing intrauterine device (most effective for reducing menstrual blood loss) 2, 5
• Tranexamic acid 2
• Combined oral contraceptives 2

Correction of anemia through treatment of heavy menstrual bleeding significantly improves quality of life, with greater improvements in energy, physical functioning, social functioning, and reductions in anxiety and depression compared to women who were not anemic at baseline. 5

Monitoring and Follow-Up

• Check hemoglobin after 3-4 weeks to confirm adequate response (2 g/dL rise expected). 1, 2

• Monitor hemoglobin and red cell indices every 3 months for one year, then annually to prevent recurrence. 1, 2

• Give additional oral iron if hemoglobin or MCV falls below normal; check ferritin in doubtful cases. 1

• Further investigation is warranted only if hemoglobin cannot be restored or maintained with oral iron therapy. 1, 2

Common Pitfalls to Avoid

• Do not perform fecal occult blood testing, as it is insensitive, non-specific, and provides no diagnostic benefit in iron deficiency anemia workup. 1

• Do not use parenteral iron as first-line therapy given its risks and lack of superiority over oral preparations. 1

• Do not undertreat or normalize the condition, as both heavy menstrual bleeding and iron deficiency adversely impact quality of life, cognitive function, work productivity, and school performance on a daily basis. 3, 4

• Only 8% of anemic women with heavy menstrual bleeding receive iron supplementation despite its high prevalence, representing a significant treatment gap. 5

Impact on Quality of Life and Long-Term Outcomes

Iron deficiency and iron deficiency anemia in women with heavy menstrual bleeding have serious clinical consequences beyond anemia itself, affecting physical and emotional health, cognitive function, and overall well-being. 6, 3, 4 There is increasing evidence that iron deficiency in early pregnancy may adversely impact fetal neurodevelopment with enduring effects on cognitive and psychological disorders, making iron repletion in reproductive-aged women critically important. 3, 4