Prevention and Management of Iron Deficiency Anaemia in Pregnancy and the Puerperium (1195)

Normal ranges in pregnancy are:

A raised ferritin result can be a transient inflammatory marker. If a serum ferritin result is >270 µg/l, repeat bloods and consultant review are indicated. If oral iron has previously been prescribed, treatment should be paused until further blood results are reviewed, and an individualised plan agreed.

Anaemias that present with a low haemoglobin but a normal or high ferritin (>30µg/l) need careful review. There are other causes of anaemia and iron therapy may not be the appropriate treatment.

Consider other causes of anaemia e.g. folate or Vitamin B12 deficiency and check levels. If there is a strong clinical suspicion of iron deficiency anaemia, consider checking transferrin (request “iron studies” on Trakcare).

These conditions

• Thalassemia trait
• Sickle cell disease (HbSS or HbSC)
• Haemolytic anaemias (e.g. Hereditary spherocytosis)

can be associated with iron overload and therefore iron replacement is relatively contraindicated. Patients are likely to know they have these conditions.

Always consider the Hb result in conjunction with the serum ferritin result to confirm iron deficiency and exclude iron overload.

Discussion with a haematologist should take place before giving iron to women with these conditions.

A. First Line: Oral Iron

The first line iron therapy for both prevention and treatment of anaemia is one tablet of oral iron once daily. Recent evidence shows once daily dosing is as effective as twice or three times a day but has fewer side effects, so compliance is increased. Alternate day dosing is possible for women unable to tolerate daily dosing.

Ferrous fumarate or ferrous sulphate are suitable oral iron preparations. Sodium feredetate 5-10ml daily is a liquid alternative.

Women should be offered advice on how to take iron

• In the morning
• On an empty stomach
• With orange juice (or other source of vitamin C)
• Avoid tea or coffee and milk for two hours as they can reduce absorption of iron.
• Some medications, including antacids, Thyroxine, calcium tablets and others interact with iron and should be taken at different times. If further advice is needed discuss with a pharmacist.

All women commenced on oral iron should continue on oral iron throughout the pregnancy, and for three months postpartum. For women commencing iron in the postnatal period oral iron should continue for at least three months.

Prescription requests to GPs should ideally be made through Clinical Portal. Local alternative arrangements may be in place in some areas. Women can be notified of results and prescription requests through the Badger App. Midwives can use the Midwifery Formulary to supply oral iron NMC | Practising as a Midwife in the UK.

B. Monitoring for a response to oral iron therapy

When oral iron is commenced as treatment for iron deficiency anaemia the effectiveness of the treatment should be monitored.

• Check Hb and reticulocyte count 2-4 weeks after starting oral iron as treatment for iron deficiency anaemia.
• Blood tests may be delayed until the patient’s next appointment if treatment started before 20 weeks gestation unless Hb≤80g/l (early monitoring required).
• Reticulocyte count will increase prior to rise in Hb and will indicate that red blood cell production is responding to therapy
• If no response in reticulocyte count at 2 weeks, review the diagnosis / compliance.
• Response will depend on the initial degree of iron deficiency, patient requirements e.g. multiple pregnancy, and compliance.

Discussion with the obstetric team for individualised management is essential when

• Hb <70g/l
• Significant symptoms of anaemia
• Advanced gestation >34/40
• No response to treatment after 2-3 weeks of correctly taken oral iron

C. Second Line: Intravenous Iron

Intravenous iron is an alternative to oral iron for the treatment of anaemia. Careful consideration should be given to the use of intravenous iron as a range of common to rare side effects can be experienced.

It is intended for the treatment of significant iron deficiency anaemia – low haemoglobin and low ferritin in consultation with the obstetric team.

Indications for intravenous iron include

• Known malabsorption condition;
• Late pregnancy >34/40 gestation if Hb < 80g/l and iron deficient;
• Postpartum in stable patient to avoid blood transfusion.

If a woman is not taking oral iron as recommended, or reports poor tolerance of oral iron, intravenous iron is not indicated. The second line in this circumstance should instead be to discuss and offer (see section 10a)

• alternative iron preparations
• alternate day dosing
• optimising absorption of oral iron
• dietary sources of iron.

It is essential that ferritin levels are checked prior to intravenous iron.

Contraindications for intravenous iron

• History of anaphylaxis or allergy to intravenous iron
• First trimester (possibly teratogenicity)
• Acute/chronic infection
• Chronic liver disease.

Refer to the GGC guideline for Iron Deficiency Anaemia (IDA) in Adults: Oral and Intravenous Iron Therapy Treatment available on Right Decisions platform - Iron Deficiency Anaemia (IDA) in Adults: Oral and Intravenous Iron Therapy Treatment (662) | Right Decisions This contains prescribing and administration information.

Feristark (ferric carboxymaltose) should be used in obstetrics.

Please note it is recommended that oral iron is stopped 48h prior to administration of intravenous iron and should be withheld for five days after, if ongoing oral treatment is required.  

Hypersensitivity reactions

IV iron preparations can cause serious hypersensitivity reactions, these are rare but include life-threatening and fatal anaphylactic and anaphylactoid reactions. These reactions can occur even when a previous administration has been tolerated. The steps outlined in the administration checklists should be taken to monitor patients during and for at least 30 minutes after every administration.  If hypersensitivity reactions / signs of intolerance occur during administration, the treatment should be stopped immediately and appropriate management initiated. 

Extravasation  

Paravenous leakage at the infusion site may lead to irritation and potentially permanent brown discolouration of the skin. Patients should be informed about the possibility of discolouration and advised to report any signs of irritation or pain at the infusion site immediately. The most effective safeguard is to visually inspect the infusion site regularly. The steps outlined in the administration checklists should be taken to monitor the infusion site during and for at least 30 minutes following administration. 

All women commenced on oral iron during pregnancy should continue on oral iron for three months postpartum.

The immediate postnatal management of anaemia will be determined by haemoglobin levels and a woman’s clinical condition. Refer to GGC Guideline Blood Transfusion in Stable Postpartum Patients

Postnatal

Intravenous iron can be used in a stable postpartum woman who is not actively bleeding or requiring immediate increase in Hb. An increase in haemoglobin of 30g/l can be expected in 14 days.

Booking appointment (pdf)

28 & 34/36 week (pdf)

Postnatal (pdf)

Patient Information Leaflet on anaemia (pdf)

Patient Information Leaflet on IV Iron (pdf)

Letter to GP (pdf)