Causes of Iron Deficiency Anemia in a 30-Year-Old Female
In a 30-year-old woman, menstrual blood loss (especially menorrhagia), pregnancy, and breastfeeding are the primary causes of iron deficiency anemia, occurring in 5-10% of premenopausal women. 1
Primary Causes in This Age Group
Gynecologic and Reproductive Factors
- Menstrual blood loss is the leading cause, particularly menorrhagia (heavy menstrual bleeding), though history alone is unreliable for quantifying blood loss 1
- Pregnancy and breastfeeding create increased iron demands and are major contributors 1
- Iron deficiency affects 38% of nonpregnant reproductive-age women without anemia, and 13% have iron-deficiency anemia 2
- During third trimester pregnancy, iron deficiency affects up to 84% of women 2
Dietary and Absorption Issues
- Poor dietary iron intake is a significant factor, especially in women of lower socioeconomic status who have decreased access to iron-rich foods 1, 3
- Celiac disease must be screened for, as it is found in 3-5% of all IDA cases and causes malabsorption 1
- Previous gastrectomy, chronic PPI therapy, gastric atrophy, bacterial overgrowth, or gut resection can impair iron absorption 4
Other Blood Loss Sources
- NSAID use causing gastrointestinal mucosal damage 1, 4
- Blood donation 4, 2
- Urinary tract bleeding (check for hematuria) 1
- Epistaxis 4
When to Suspect GI Pathology (Less Common in This Age)
Underlying GI pathology is uncommon in young women with IDA 1, but further investigation beyond celiac screening is warranted if:
- Age over 50 years (strong predictor of malignancy risk) 1
- Non-menstruating status (e.g., post-hysterectomy) 1
- Red flag GI symptoms present 1
- Family history of colorectal cancer in two first-degree relatives, or one affected before age 50 1
- Recurrent or persistent IDA disproportionate to menstrual losses 1
Essential Diagnostic Approach
Initial Testing
- Serum ferritin is the most specific test: <15 μg/L confirms iron deficiency (specificity 0.99), while <30 μg/L indicates low stores 1
- In inflammatory conditions, ferritin may be falsely normal; consider values <45 μg/L as potentially significant 1
- Celiac serology (tissue transglutaminase antibody) should be performed in all premenopausal women with IDA 1
- Urinalysis or urine microscopy to exclude urinary tract bleeding 1
Investigation Algorithm for Young Women
- Under age 45 without upper GI symptoms: Screen for celiac disease with antiendomysial antibody (and IgA measurement to exclude IgA deficiency) 1
- With upper GI symptoms: Perform endoscopy and small bowel biopsy 1
- Colonic investigation: Only indicated if there are specific clinical indications, not routinely needed in women under 45 1
Critical Clinical Pitfalls
- Multiple causes often coexist—finding menorrhagia does not exclude celiac disease or other pathology 4, 5
- Pictorial blood loss assessment charts have only 80% sensitivity/specificity for detecting menorrhagia, so clinical judgment remains important 1
- Ferritin is an acute phase protein and may appear normal despite iron deficiency in inflammatory conditions 1
- Failure to respond to iron therapy (hemoglobin should rise by 2 g/dL after 3-4 weeks) indicates poor compliance, misdiagnosis, continued blood loss, or malabsorption 1, 5