Iron for Pregnancy Support
Iron deficiency in pregnancy is common and consequential; screening and repletion are standard care.
Overview
Verdict
A Cochrane review of 43,274 participants found daily oral iron in pregnancy reduced maternal anaemia and low birthweight, with more side effects and haemoconcentration at higher doses.
How It Works
Downstream effects
Dosing & Protocol
Doses used in trials and guidance
| Situation | Dose | Schedule | Notes |
|---|---|---|---|
| Routine antenatal prophylaxis | 30-60 mg elemental iron | Once daily | WHO guidance for pregnancy, alongside folic acid |
| Intermittent regimen | 120 mg elemental iron | Once or twice weekly | An option where daily iron is not tolerated |
| Diagnosed iron deficiency anaemia | 65 mg elemental iron | Daily or alternate days, as directed | Treatment doses should be set and monitored by your maternity team |
| Alongside folic acid | 400 micrograms folic acid | Daily, ideally from preconception | Separate requirement for neural tube defect prevention |
Higher doses increase side effects and haemoconcentration without proportionate benefit. Follow the regimen your maternity care team gives you.
Simple protocol
- 1
Follow your antenatal guidance
Iron in pregnancy is part of supervised care, and local recommendations vary by country and by your blood results.
- 2
Take the lowest effective dose· Through pregnancy as advised
30-60 mg elemental iron daily is the routine prophylactic range; higher doses add side effects and haemoconcentration.
- 3
Take it with vitamin C, away from tea and calcium
Orange juice helps absorption; tea, coffee, milk and calcium supplements reduce it substantially.
- 4
Switch strategy if you cannot tolerate it
Alternate-day or twice-weekly dosing, or a gentler salt such as ferrous bisglycinate, often solves it. Tell your midwife rather than stopping silently.
- 5
Manage constipation early
Fluid, fibre and movement; ask before adding a laxative in pregnancy.
- 6
Attend your blood tests
Haemoglobin is checked through pregnancy so the dose can be adjusted in either direction.
Evidence
Studies linked to this pairing.
Daily oral iron supplementation during pregnancy
Pena-Rosas JP, De-Regil LM, Garcia-Casal MN +1 more
Daily iron reduced maternal anaemia and low birthweight, with more side effects at higher doses
- Maternal anaemia
- Reduced by daily oral iron
- Low birthweight
- Reduced by daily oral iron
- Participants
- 43,274 across pooled randomised trials
- Evidence tier
- Cochrane systematic review and meta-analysis
- Dose effect
- Higher doses increased side effects and haemoconcentration
- Main limitation
- Benefit varies with baseline iron status and background anaemia prevalence
Safety
More iron is not better in pregnancy
Higher doses increased side effects and haemoconcentration in the pooled trial data. Take the dose your maternity team advises and attend the blood tests that guide it.
Interactions & Conflicts
Interactions and cautions
| Interacts with | Severity | Mechanism | Action |
|---|---|---|---|
| Haemochromatosis or thalassaemia | high | Risk of iron overload | Only under specialist supervision |
| Levothyroxine | high | Iron reduces thyroxine absorption, which matters in pregnancy | Separate by at least 4 hours |
| Tetracycline and quinolone antibiotics | high | Mutual chelation reduces absorption | Separate by at least 2-4 hours |
| Calcium supplements and dairy | moderate | Calcium inhibits non-haem iron absorption | Take at different times of day |
| Tea and coffee | moderate | Polyphenols bind iron in the gut | Separate by an hour either side |
| Young children in the household | high | Iron tablets are a leading cause of fatal childhood poisoning | Store out of reach in child-resistant packaging |
References
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.