What is the recommended Iron (Fe) and Folic Acid (FA) supplementation regimen for pregnant women?

Iron and Folic Acid Supplementation in Pregnancy

All pregnant women should begin daily oral iron supplementation (30 mg elemental iron) at their first prenatal visit, combined with 400 μg (0.4 mg) folic acid, ideally starting at least 4 weeks before conception and continuing throughout pregnancy. 1, 2

Standard Prophylactic Regimen for All Pregnant Women

Iron Supplementation

• Start 30 mg elemental iron daily at the first prenatal visit 1, 2
• Most prenatal vitamins contain 30-48 mg elemental iron, which meets this requirement 1, 3
• Continue throughout pregnancy and into the postpartum period 2
• Take at bedtime to minimize gastrointestinal side effects 2

Folic Acid Supplementation

• 400 μg (0.4 mg) daily for all women of childbearing age 1
• Begin at least 4 weeks prior to planned conception 1
• Continue through at least the first trimester 1
• This dose effectively prevents neural tube defects without additional benefit from higher doses in low-risk women 1

Treatment Doses for Confirmed Iron Deficiency Anemia

When iron deficiency anemia is diagnosed, increase to 60-120 mg elemental iron daily 1, 2

Monitoring Treatment Response

• Recheck hemoglobin or hematocrit after 4 weeks of treatment 1, 2
• Expected response: hemoglobin should increase by ≥1 g/dL or hematocrit by ≥3% 1, 2
• Once hemoglobin normalizes for gestational age, decrease back to 30 mg/day 1, 2

When Treatment Fails

• If no response after 4 weeks despite compliance, obtain MCV, RDW, and serum ferritin 1, 2
• Consider thalassemia minor or sickle cell trait in women of African, Mediterranean, or Southeast Asian ancestry 1, 2
• Refer to a specialist if hemoglobin <9.0 g/dL or hematocrit <27.0% 1, 2

High-Risk Women Requiring Higher Folic Acid Doses

Women with personal, family, or prior pregnancy history of neural tube defects require 4 mg (4000 μg) folic acid daily 1, 4

High-Risk Criteria Include:

• Personal history of neural tube defects 1
• Prior offspring with neural tube defects 1, 4
• First or second-degree relatives with neural tube defects 1
• Type 1 diabetes mellitus 1
• Exposure to high-risk medications (valproic acid, carbamazepine, methotrexate) 1

High-Risk Dosing Schedule:

• 4 mg folic acid daily starting at least 12 weeks before conception 1, 4
• Continue 4 mg daily through 12 weeks gestation 1, 4
• After 12 weeks gestation, reduce to 0.4-1.0 mg daily for remainder of pregnancy 1, 4

Optimizing Iron Absorption

Timing and Co-Administration

• Separate iron supplements from calcium supplements and antacids by several hours 2, 3, 5
• Calcium and antacids significantly decrease iron absorption 2, 3
• Take with vitamin C-containing foods to enhance absorption 2, 3

Dietary Considerations

• Pregnant women require 27 mg iron daily from all sources 1, 3
• Vegetarian women may require almost twice as much iron since non-heme iron (plant sources) is less well absorbed than heme iron (animal sources) 1, 3, 5
• Encourage iron-rich foods alongside supplementation 1, 2

Special Population Considerations

Women at Higher Risk for Iron Deficiency

• Non-Hispanic Black and Mexican American women have higher prevalence of iron deficiency 1, 3
• Women with short intervals between pregnancies 3
• Women with gastrointestinal conditions affecting absorption 3
• These women may require 60-100 mg elemental iron daily from early pregnancy 1, 3

Postpartum Management

• Screen for anemia at 4-6 weeks postpartum only if risk factors present (anemia continued through third trimester, excessive blood loss at delivery, multiple birth) 1, 2
• If postpartum iron deficiency anemia diagnosed, treat with 60-120 mg elemental iron daily 1, 2
• Continue treatment for 2-3 months after hemoglobin normalizes 1, 2

Common Pitfalls to Avoid

• Failing to separate calcium and iron doses, which dramatically reduces iron absorption 2, 3, 5
• Not identifying high-risk women who need 4 mg folic acid instead of standard 0.4 mg 1, 3
• Discontinuing iron treatment too early before stores are replenished 2
• Relying solely on hemoglobin levels, as hemoglobin can be normal despite depleted iron stores 5
• Not screening for pernicious anemia before high-dose folic acid, though this is rare and routine screening is not required 6, 4

Expected Side Effects

Iron Supplementation

• Gastrointestinal effects (nausea, constipation, diarrhea) are common 2
• Darkening of stool or urine is expected and harmless 2, 3
• Possible staining of teeth and gums 2, 3
• Side effects more common with daily 60-120 mg doses than prophylactic 30 mg doses 1

Folic Acid Safety

• Folic acid is safe during pregnancy 6
• Doses above 0.4 mg daily may theoretically mask pernicious anemia, but this should not prevent appropriate supplementation when indicated 6
• High-risk women requiring 4 mg folic acid should take additional folic acid-only tablets rather than multiple prenatal vitamins 4