Please read Dr Ying Yu’s latest article – on Iron Deficiency in Pregnancy

Iron deficiency anaemia(IDA) is a common condition in pregnancy that can have significant adverse effects on the health of mother and baby.  Pregnant women with IDA are at greater risk of blood transfusion, life-threatening bleeding, fetal growth restriction, preterm birth and perinatal death.

Iron deficiency alone is defined by haemoglobin level within normal limits with serum ferritin level below 30mcg/L and is a precursor to IDA.  Routine screening for IDA by measuring haemoglobin level +/-ferritin level should occur at the first antenatal appointment and at 28 weeks of gestation.  A haemoglobin level of less than 110g/L before 20 weeks of gestation or less than 105g/L at or after 20 weeks gestation is considered abnormal.

First line treatment for IDA is oral iron supplementation. Therapeutic oral iron supplementation containing 100-200mg of elemental iron daily is recommended. If a rapid increase in haemoglobin is not required, alternate daily or intermittent (2-3 times weekly) doses of 60-100mg may lead to improved adherence and have lower side effect with similar results.  Most pregnancy multivitamins do not contain sufficient iron for treatment of IDA.  Oral iron should be given 1-2 hours before food, to improve absorption.  Medications that can interfere with absorption include calcium, antacids, thyroid medications and some antibiotics.  Foods that interfere with absorption include tea, coffee, milk, chocolate and cola.  Common side effects of oral iron include constipation, diarrhoea, abdominal pain, discolouration of stools and nausea.  Oral iron should be continued until haemoglobin is within normal range, and for 6-8 weeks after this time, to correct iron stores.

Intravenous iron supplementation should only be considered when oral iron therapy has failed, is not tolerated or rapid replacement is required to optimise iron stores and haemoglobin level. It is important to note that IV iron may have side effects including allergic reactions, skin staining due to extravasation and is contraindicated in the first trimester.

Excellent resources are available from the Australian Red Cross Blood service Toolkit in Maternity Blood Management. (

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