Beta We are building this new website to better deliver information. Learn more about this site.

Antenatal care provides an opportunity to identify women with possible anaemia. If anaemia is diagnosed, supplementation with the deficient nutrient (most commonly iron) may be advised where indicated.

30.1 Background

Anaemia is a lower than normal concentration of haemoglobin or number of red blood cells, which results in reduced capacity of the blood to carry oxygen. During pregnancy, the WHO criteria for mean minimum normal haemoglobin concentration in healthy pregnant women is 110 mg/dL in the first half of pregnancy and 105 mg/ dL in the second. Iron deficiency is the most common cause of anaemia in pregnancy worldwide (WHO 2001), but other deficiencies may also cause anaemia:

  • iron deficiency: demand for iron is increased during pregnancy (NPS 2010) and insufficient iron intake or absorption (eg diet poor in iron-rich foods and/or rich in foods that diminish iron absorption) or blood loss (eg due to gastrointestinal parasites) (ACOG 2008) can result in microcytic anaemia
  • folate deficiency: demand for folate is also increased during pregnancy and inadequate dietary intake, prolonged vomiting or impaired absorption (eg due to gastric bypass surgery or gastrointestinal conditions) can result in macrocytic anaemia
  • vitamin B12 deficiency: prolonged inadequate intake (eg limited access to source foods or vegetarian diet) or impaired absorption (eg due to gastric bypass surgery, pernicious anaemia or gastrointestinal conditions) can result in macrocytic anaemia
  • haemoglobinopathies: these include sickle cell anaemia and thalassaemia (see Chapter 31).

Symptoms of anaemia include general weakness and tiredness but the threshold concentrations of haemoglobin at which these symptoms occur in pregnancy is not known (Reveiz et al 2011).

30.1.1 Prevalence of iron, folate and vitamin B12 deficiency during pregnancy

Estimates suggest that one-quarter of the world’s population has anaemia. The burden of anaemia is considerably higher among indigenous populations compared to the general population (Khambalia et al 2011).

The prevalence of iron-deficiency anaemia during pregnancy is generally low (< 20%) in developed countries (van den Broek 2003) and higher (35–75%) in developing countries (Africa, Asia, South America) (van den Broek 2003; Kalaivani 2009) and areas of socioeconomic disadvantage (USPSTF 2006). Reported predictors for having anaemia by 32 weeks gestation include young maternal age, non-white ethnic origin and increasing parity (Barroso et al 2011).

Few studies have reported the prevalence of iron-deficiency anaemia during pregnancy in Australia. Iron-deficiency anaemia was identified in 18% of pregnant women in a Tasmanian study (n=2,654) (Khalafallah et al 2010) and in 11% of pregnant women in a South Australian study (n=430) (Zhou et al 2006).

Data from Queensland suggest higher prevalence of iron-deficiency anaemia during pregnancy among Aboriginal than non-Indigenous women (Wills & Coory 2008). Smaller studies have found a prevalence of anaemia during pregnancy among Aboriginal women of 50% in remote Northern Territory communities (Bar-Zeev et al 2013), 12% across 34 Aboriginal community health services (range 3–22%) (n=535) (Rumbold et al 2011) and 10% in Brisbane (n=1,523) (Stapleton et al 2011).

Data from Western Australia and South Australia show higher prevalence of iron-deficiency anaemia during pregnancy among adolescent (14%) than adult women (6%) and among Aboriginal (23–25%) compared with non-Indigenous (8–10%) adolescent women (Westernberg et al 2002; Lewis et al 2009).

Mandatory fortification of flour with folic acid has reduced the prevalence of low folate levels among Australian women of childbearing age (0.16% in 2010) (Brown et al 2011). A Western Australian study found low folate levels in 10% of Aboriginal women before flour fortification (Maxwell et al 2012).

Vitamin B12 deficiency is common in most of the developing world (Stabler & Allen 2004; Allen 2009). Few studies have examined the prevalence of vitamin B12 deficiency in Australia (Flood et al 2006). However, there is emerging evidence of vitamin B12 deficiency among refugees due to limited or no sources of animal foods before resettlement (Benson et al 2010; Benson et al 2013).

Preventing iron deficiency (through inclusion of iron-rich foods in the diet and/or iron supplementation) is discussed in Section 11.3.2.

30.1.2 Risks associated with iron, folate and vitamin B12 deficiency during pregnancy

Severe iron-deficiency anaemia (haemoglobin concentration <70 mg/dL) can cause cardiac failure, (Lops 1995; WHO 1992; Williams & Wheby 1992) and reduce tolerance of blood loss associated with birth. It is unclear whether mild to moderate anaemia is associated with poor outcomes (Reveiz et al 2011).

Deficiencies of folate (De-Regil et al 2010) or vitamin B12 (Molloy et al 2009) during pregnancy are associated with neural tube defects.

30.2 Testing for anaemia

Routinely offering a full blood count early in pregnancy and at 28 weeks is recommended in the United Kingdom (NICE 2008) and in Australia (RANZCOG 2009). Initial haemoglobin concentration is usually assessed in the context of this full blood count.

30.2.1 Assessing haemoglobin concentration

During pregnancy, maternal red cell mass and plasma volume increase and the haemoglobin concentration is reduced (NICE 2008). Haemoglobin is therefore checked against gestation-related thresholds.

Table F1: Assessing haemoglobin concentration during pregnancy

A list of haemoglobin concentration during pregnancy. This table is a list of gestational age and Minimum haemoglobin concentration.
Gestational age Minimum haemoglobin concentration
0–20 weeks 110 mg/dL
20+ weeks 105 mg/dL

Source: (WHO 1993).

 

Recommendation

  • Consensus-based
  • XXXVII

Routinely offer testing for haemoglobin concentration to pregnant women early in pregnancy (at the first visit) and at 28 weeks gestation.

Approved by NHMRC in June 2014; expires June 2019 UNDER REVIEW

Recommendation

  • Practice point
  • SS

In areas where prevalence of iron-deficiency anaemia is high consider testing ferritin at the first antenatal visit.

Approved by NHMRC in June 2014; expires June 2019 UNDER REVIEW

30.2.2 Further investigations

Haemoglobin concentration is not sensitive enough to be the sole means of diagnosing anaemia. Diagnostic tests include:

  • full blood count (if this has not already been conducted)
  • serum ferritin, which is the most sensitive single test to detect adequate iron stores (90% sensitivity at a cut-off of 30 mg/litre) (Breymann 2002)
  • specific tests for folate and vitamin B12, if mean cell volume is high.

Recommendation

  • Practice point
  • TT

Further investigation is required for women with a low haemoglobin concentration for their gestational stage. Repeat testing at 36 weeks may also be required for women who have symptoms or risk factors for anaemia or who live in or have come from an area of high prevalence. 

Approved by NHMRC in June 2014; expires June 2019 UNDER REVIEW

30.3 Treating iron-deficiency anaemia

30.3.1 Effectiveness and safety of treatments for iron-deficiency anaemia

The evidence on treatments for iron-deficiency anaemia covers a very wide range of supplements, doses and routes of administration and focuses on changes in maternal haemoglobin concentration.

  • Iron supplementation improves maternal haemoglobin concentrations, but there is a lack of evidence about the overall benefits of treating mild iron-deficiency anaemia in pregnancy (Reveiz et al 2011).
  • Oral iron can cause gastrointestinal adverse effects (eg nausea, constipation) (Reveiz et al 2011). Intramuscular or intravenous iron is more effective than oral iron, but may have adverse effects (venous thrombosis and allergic reactions for intravenous treatment and pain, discolouration and allergic reactions for intramuscular treatment) (Reveiz et al 2011).

Iron as part of general nutritional supplementation is discussed in Section 11.3.2. Given the lack of evidence on outcomes, the recommendation is not to routinely offer iron supplementation to women during pregnancy.

Recommendation

  • Grade B
  • 32

Advise iron supplementation for women identified as having iron-deficiency anaemia. 

Approved by NHMRC in June 2014; expires June 2019 UNDER REVIEW

Recommendation

  • Practice point
  • UU

Oral iron remains first-line treatment for iron-deficiency anaemia identified in the antenatal period. Intravenous iron should be offered to women who do not respond to oral iron or are unable to comply with therapy. In some remote settings, intramuscular iron may be administered by a health professional who does not have intravenous endorsement or where intravenous iron cannot be accessed.

Approved by NHMRC in June 2014; expires June 2019 UNDER REVIEW

30.3.2 Dose of supplementation 

Recent studies provide high-level evidence on lower doses of iron supplementation. Iron supplements that are low dose (eg 20 mg) or taken less often than daily appear to be effective in treating anaemia in pregnancy with fewer gastrointestinal side effects compared with high-dose (eg 80 mg) or daily supplements (de Souza et al 2004; Sharma et al 2004; Zhou et al 2009; Reveiz et al 2011).

Recommendation

  • Grade B
  • 33

Advise women with iron-deficiency anaemia that low-dose iron supplementation is as effective as high dose, with fewer side effects.

Approved by NHMRC in June 2014; expires June 2019 UNDER REVIEW

30.3.3 Other considerations

Treatment for hookworm infestation should also be considered in areas of high prevalence.

30.4 Discussing anaemia

When haemoglobin concentration is low, points for discussion include:

  • while anaemia in pregnancy is most commonly associated with iron deficiency, deficiencies of folate or vitamin B12 also result in anaemia and further tests are required to identify the cause
  • if a deficiency is identified, supplementation with the appropriate nutrient can correct the deficiency
  • supplements can be combined with foods rich in the relevant nutrient:
    • iron-rich foods include meat, seafood and poultry; including a vitamin C rich fruit or vegetable in each meal and limiting tea and coffee to between meals aids absorption (Marsh et al 2009)
    • foods rich in folate include fortified bread and cereals, dried beans and peas, dark green vegetables and citrus fruit and juice
    • foods that contain vitamin B12 include meat, eggs, milk and cheese.

30.5 Practice summary: anaemia

When

Early in pregnancy and at 28 weeks gestation.

Who

  • Midwife
  • GP
  • obstetrician
  • Aboriginal and Torres Strait Islander Health Practitioner
  • Aboriginal and Torres Strait Islander Health Worker
  • multicultural health worker.

What

  • Discuss the reasons for testing for anaemia
    Explain that anaemia causes tiredness and can have other effects on the pregnancy.
  • Explain the causes of anaemia
    Iron-deficiency anaemia is common during pregnancy. Other causes of anaemia may be a consideration for women who live in or have come from areas where folate or vitamin B12 deficiencies are common.
  • Take a holistic approach
    Consider the availability of iron-rich foods appropriate to the woman’s cultural practices and preferences and the affordability of supplements. For women taking supplements for iron-deficiency, explore culturally appropriate, low cost ways for women to increase their fibre and fluid intake if they are experiencing constipation.
  • Consider referral
    If there is concern about the quality of dietary iron intake or if the woman would like information about nutrition for herself and her family, consider referral to an accredited dietitian.
  • Document and follow-up
    When a woman is tested for anaemia, tell her the results and note them in her antenatal record. Have a system in place so that women with iron-deficiency anaemia during pregnancy are given information about iron supplementation and receive ongoing follow-up, including further investigation if anaemia does not resolve after pregnancy.

30.6 Resources

  • Remote Primary Health Care Manuals. (2017). Anaemia (weak blood) in pregnancy. In: Women’s Business Manual (6th edition). Alice Springs, NT: Centre for Remote Health.

References

  • ACOG (2008) Practice bulletin: anemia in pregnancy. Obstet Gynecol 112(1): 201–07.
  • Allen L (2009) How common is vitamin B-12 deficiency? Am J Clin Nutr 89: 693–96S.
  • Barroso S, Allard BC, Kahan C et al (2011) Prevalence of maternal anaemia and its predictors: a multi-centre study. Eur J Obstet Gynecol Reprod Biol 159(1): 99–105.
  • Bar-Zeev S, Barclay L, Kruske S et al (2013) Use of maternal health services by remote dwelling Aboriginal women in northern Australia and their disease burden. Birth: 40(3): 172-81.
  • Benson J, Maldari T, Turnbull T (2010) Vitamin B12 deficiency. Why refugee patients are at high risk. Aust Fam Phys 39(4): 215–17.
  • Benson J, Phillips C, Kay M et al (2013) Low vitamin B12 levels among newly-arrived refugees from Bhutan, Iran and Afghanistan: A multicentre Australian study. PLoS ONE 8(2): e57998.
  • Breymann C (2002) Iron supplementation during pregnancy. Fetal Maternal Med Rev 13: 1–29.
  • Brown RD, Langshaw MR, Uhr EJ et al (2011) The impact of mandatory fortification of flour with folic acid on the blood folate levels of an Australian population. Med J Aust 194(2): 65–67.
  • de Souza AI, Batista Filho M, Ferreira LO et al (2004) The effectiveness of three regimens using ferrous sulfate to treat anemia in pregnant women. Rev Panam Salud Publica 15(5): 313–19.
  • de-Regil LM, Fernández-Gaxiola AC, Dowswell T et al (2010) Effects and safety of periconceptional folate supplementation for preventing birth defects. Cochrane Database of Systematic Reviews DOI: 10.1002/14651858.CD007950.pub2.
  • Flood VM, Smith W, Webb K et al (2006) Prevalence of low serum folate and vitamin B12 in an older Australian population. Aust NZ J Public Health 30(1): 38–41.
  • Kalaivani, K (2009) Prevalence and consequences of anaemia in pregnancy. Ind J Med Res 130(5): 627–33.
  • Khalafallah A, Dennis A, Bates J et al (2010) A prospective randomized, controlled trial of intravenous versus oral iron for moderate iron deficiency anaemia of pregnancy. J Int Med 268(3): 286–95.
  • Khambalia AZ, Aimone AM, Zlotkin SH (2011) Burden of anemia among indigenous populations. Nutr Rev 69(12): 693–719.
  • Lewis L, Hickey M, Doherty DA et al (2009) How do pregnancy outcomes differ in teenage mothers? A Western Australian study. Med J Aust 10: 537–41.
  • Lops VR, Hunter LP, Dixon LR (1995) Anemia in pregnancy. Am Fam Phys 51: 1189–97.
  • Marsh K, Zeuschner C, Saunders A et al (2009) Meeting nutritional needs on a vegetarian diet. Aust Fam Phys 8(8): 600–02.
  • Maxwell SJ, Brameld KJ, Bower C et al (2012) Baseline investigations of folate status in Aboriginal and non-Aboriginal West Australians prior to the introduction of mandatory fortification. Aust NZ J Obstet Gynaecol doi: 10.1111/j. 1479-828X.2012.01484.x. [Epub ahead of print].
  • Molloy AM, Kirke PN, Troendle JF et al (2009) Maternal vitamin B12 status and risk of neural tube defects in a population with high neural tube defect prevalence and no folic acid fortification. Pediatr 123(3): 917–23.
  • NICE (2008) Antenatal Care. Routine Care for the Healthy Pregnant Woman. National Collaborating Centre for Women’s and Children’s Health. Commissioned by the National Institute for Health and Clinical Excellence. London: RCOG Press.
  • NPS (2010) Iron deficiency anaemia. National Prescribing Service. NPS News 70.
  • RANZCOG (2009) Pre-pregnancy Counselling and Routine Antenatal Assessment in the Absence of Pregnancy Complications (C-Obs 3). Melbourne: Royal Australian and New Zealand College of Obstetricians and Gynaecologists.
  • Reveiz L, Gyte GML, Cuervo LG et al (2011) Treatments for iron-deficiency anaemia in pregnancy. Cochrane Database of Systematic Reviews Issue 10. Art. No.: CD003094. DOI: 10.1002/14651858.CD003094.pub3.
  • Rumbold AR, Bailie RS, Si D et al (2011) Delivery of maternal health care in Indigenous primary care services: baseline data for an ongoing quality improvement initiative. BMC Pregnancy Childbirth 11: 16.
  • Sharma JB, Jain S, Mallika V et al (2004) A prospective, partially randomized study of pregnancy outcomes and hematologic responses to oral and intramuscular iron treatment in moderately anemic pregnant women. Am J Clin Nutr 79(1): 116–22.
  • Stabler S & Allen R (2004) Vitamin B12 deficiency as a world-wide problem. Annu Rev Nutr 24: 299–326.
  • Stapleton H, Murphy R, Gibbons K et al (2011) Evaluation of the Mater Mothers’ Hospitals Murri Antenatal Clinic. Brisbane: Midwifery Research Unit, Mater Mothers’ Hospitals and Australian Catholic University.
  • USPSTF (2006) Screening for Iron Deficiency Anemia in Childhood and Pregnancy: Update of the 1996 US Preventive Services Task Force Review. AHRQ Publication No. 06-0590-EF-1.
  • van den Broek N (2003) Anaemia and micronutrient deficiencies. Brit Med Bull 67: 149–60.
  • Westenberg L, van der Klis AM, Chan A et al (2002) Aboriginal teenage pregnancies compared with non-Aboriginal in South Australia 1995–1999. Aust NZ J Obstet Gynaecol 42: 187–92.
  • WHO (1992) The Prevalence of Anaemia in Women: a Tabulation of Available Information (WHO/MCH/ MSM/92). 2nd Edition. Geneva: World Health Organization.
  • WHO (1993) Prevention and Management of Severe Anaemia in Pregnancy. Geneva: World Health Organization.
  • WHO (2001) Iron Deficiency Anaemia, Assessment, Prevention, and Control: a Guide for Programme Managers. Geneva: World Health Organization.
  • Williams MD & Wheby MS (1992) Anemia in pregnancy. Medical Clinics of North America 76: 631–47.
  • Wills R & Coory MD (2008) Effect of smoking among indigenous and non-indigenous mothers on preterm birth and full-term low birthweight. Med J Aust 9: 490–494.
  • Zhou SJ, Gibson RA, Crowther CA et al (2006) Effect of iron supplementation during pregnancy on the intelligence quotient and behavior of children at 4 y of age: long-term follow-up of a randomized controlled trial. Am J Clin Nutr 83(5): 1112–17.
  • Zhou SJ, Gibson RA, Crowther CA et al (2009) Should we lower the dose of iron when treating anaemia in pregnancy? A randomized dose-response trial. Eur J Clin Nutr 63(2): 183–90.
Last updated: 
21 November 2018