Iron Supplementation for Prevention of Anemia in Pregnancy
For prevention of iron deficiency anemia in pregnant women, start 30 mg of elemental iron daily at the first prenatal visit. 1, 2
Primary Prevention Dosing
The Centers for Disease Control and Prevention recommends 30 mg/day of oral elemental iron starting at the first prenatal visit for all pregnant women, regardless of anemia status. 1, 2
This low-dose prophylactic regimen should continue throughout pregnancy to maintain adequate iron stores and prevent iron deficiency anemia. 2
The American College of Obstetricians and Gynecologists supports this universal supplementation approach at 30 mg/day for prevention. 2, 3
Rationale for 30 mg Daily Dose
Requirements for absorbed iron increase dramatically during pregnancy, from approximately 0.8 mg/day in the first trimester to 7.5 mg/day in the third trimester. 4, 5
Approximately 40% of women of reproductive age have ferritin ≤30 μg/L, indicating small or absent iron reserves and an unfavorable iron status for pregnancy. 4, 5
Studies demonstrate that 30-40 mg of ferrous iron taken between meals from early pregnancy to delivery efficiently prevents iron deficiency anemia. 4, 5
The Cochrane systematic review found that iron supplementation at doses ≥60 mg was associated with increased maternal side effects (25.3% versus 9.91% in controls), supporting lower prophylactic doses. 6
Treatment Doses (When Anemia Develops)
If anemia develops despite prophylaxis, increase to 60-120 mg/day of elemental iron for treatment. 1, 2, 3
Once hemoglobin or hematocrit normalizes for gestational age, the Centers for Disease Control and Prevention recommends reducing back to the maintenance dose of 30 mg/day. 1, 2
Dietary Counseling
Encourage pregnant women to eat iron-rich foods and foods that enhance iron absorption alongside supplementation. 1, 2
Dietary measures alone are inadequate to reduce the frequency of iron deficiency anemia during pregnancy. 4
Special Populations
Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron from plant sources. 7
Women with ferritin ≤30 μg/L at conception may benefit from higher prophylactic doses (60-80 mg/day) rather than the standard 30 mg/day. 5
Common Pitfall to Avoid
Do not wait until anemia develops to start iron supplementation—begin prophylaxis at the first prenatal visit, as only 15-20% of women have adequate iron reserves (≥500 mg) at conception. 5
Side effects increase significantly at doses ≥60 mg, so reserve higher doses for treatment of established anemia rather than routine prevention. 6