How should I manage iron deficiency and heavy menstrual bleeding in a non‑pregnant woman who wants to become pregnant?

Management of Heavy Menstrual Bleeding and Iron Deficiency in a Woman Planning Pregnancy

Treat her iron deficiency immediately with oral iron 60-120 mg/day of elemental iron while simultaneously addressing the heavy menstrual bleeding, as correcting iron stores before conception is critical for preventing adverse fetal neurodevelopmental outcomes and maternal complications during pregnancy. 1, 2

Immediate Iron Replacement Strategy

Start oral ferrous sulfate 325 mg daily (65 mg elemental iron) or 60-120 mg elemental iron daily as first-line therapy. 1, 3 This dose is appropriate for nonpregnant women with iron deficiency anemia and will help replenish stores before conception. 1

Monitoring Response to Treatment

• Recheck hemoglobin after 4 weeks of treatment to confirm response, expecting an increase of at least 1-2 g/dL. 1, 4
• If hemoglobin fails to rise by 1 g/dL after 4 weeks despite compliance, perform additional testing including MCV, RDW, and serum ferritin to evaluate for other causes. 1
• Continue iron supplementation for 2-3 months after hemoglobin normalizes to fully replenish iron stores, which is essential before pregnancy. 1

Alternative Iron Formulations

• Consider alternate-day dosing (ferrous sulfate 325 mg every other day) if gastrointestinal side effects limit compliance, as absorption may actually be enhanced with this regimen. 3
• Switch to intravenous iron (preferably ferric carboxymaltose) if she cannot tolerate oral iron after trying at least two different oral preparations, or if rapid repletion is needed before planned conception. 1, 2, 3

Addressing Heavy Menstrual Bleeding

Evaluate the severity and underlying cause of her heavy menstrual bleeding, as this is the primary driver of her iron deficiency and will continue to deplete iron stores. 5, 6

Key Diagnostic Considerations

• Heavy menstrual bleeding affects 5-10% of menstruating women and is the most common cause of iron deficiency in reproductive-age women. 1, 5
• Blood loss exceeding 80 mL per cycle (approximately 36 mg of iron loss) typically exceeds dietary iron absorption capacity and leads to progressive iron depletion. 7
• If she is under age 45 without gastrointestinal symptoms, focus evaluation on gynecologic causes rather than gastrointestinal investigation. 1

Treatment Options for Heavy Menstrual Bleeding

The specific treatment depends on whether she wants to conceive immediately or can delay conception:

• If conception is planned within 1-3 months: Focus on aggressive iron replacement and consider short-term medical management of bleeding (tranexamic acid during menses) that won't interfere with fertility. 7
• If she can delay conception for 3-6 months: Consider hormonal treatments (levonorgestrel IUD, combined oral contraceptives) to reduce menstrual blood loss while replenishing iron stores, then discontinue before attempting conception. 5, 6

Dietary Counseling

Counsel her to consume iron-rich foods (red meat, poultry, fortified cereals) and foods that enhance iron absorption (vitamin C-rich foods). 1, 8 This is particularly important as she prepares for pregnancy when iron demands will increase substantially. 2

Pre-Conception Optimization Timeline

Aim to normalize her hemoglobin and replenish iron stores (ferritin >30 ng/mL) before conception, as iron deficiency even in early pregnancy adversely impacts fetal neurodevelopment with lasting effects on cognitive and psychological function. 5, 6

Transition to Pregnancy

• Once pregnant, she should immediately start 30 mg/day elemental iron supplementation at the first prenatal visit as universal prophylaxis. 2, 9
• If she conceives while still anemic, increase to 60-120 mg/day of elemental iron immediately without waiting for confirmatory testing. 2, 9
• Screen for anemia at the first prenatal visit and again at 24-28 weeks gestation. 2, 9

Common Pitfalls to Avoid

• Do not assume heavy menstrual bleeding is "normal" or delay treatment – this normalization by patients and providers perpetuates iron deficiency and its adverse effects on quality of life, work productivity, and cognitive function. 5, 6
• Do not stop iron supplementation once hemoglobin normalizes – continue for 2-3 additional months to replenish stores before conception. 1
• Do not investigate for gastrointestinal causes if she is under 45 without GI symptoms – menstrual blood loss is the overwhelmingly likely cause. 1
• Warn her that oral iron causes dark stools and constipation, which are expected side effects and not reasons to discontinue therapy. 8, 4