What is anaemia in pregnancy?

Anaemia is a condition in which the blood doesn’t contain enough healthy red blood cells or haemoglobin to effectively carry oxygen around the body.¹ There are many different types of anaemia, and the causes and treatments vary depending on which kind you have.¹

During pregnancy, anaemia becomes particularly important as your body must support your growing baby while also coping with changes in your own physiology. While anaemia in pregnancy can feel worrying, it’s routinely screened for as part of antenatal care in the UK, meaning you can get the treatment you need promptly.²

Is anaemia common in pregnancy?

Anaemia during pregnancy is relatively common, particularly in the second and third trimesters, when the body’s demand for iron increases to support the growing baby. In the UK, mild anaemia is estimated to affect around 20 to 30% of pregnant women, with iron deficiency being the most common cause.²

On a global level, anaemia in pregnancy is even more widespread. According to international health data, it is estimated to affect around 35 to 40% of pregnant women worldwide, making it one of the most common nutritional concerns during pregnancy.³

The likelihood of developing anaemia can vary across pregnancy. It is less common in the first trimester, but becomes more likely as pregnancy progresses due to increased blood volume and higher iron requirements in the second and third trimesters.

The reassuring news is that anaemia in pregnancy is usually manageable when identified early. With appropriate support, such as dietary adjustments and, where recommended, iron supplementation, many women are able to restore healthy iron levels and continue with a healthy pregnancy. Regular antenatal check-ups help to monitor iron levels, meaning any issues can often be addressed promptly.

What causes anaemia in pregnancy?

The most common cause of anaemia in pregnancy is iron deficiency, but several factors can contribute. Pregnancy naturally increases blood plasma volume by approximately 30 to 50% to support the placenta and growing baby.³ This expansion can outpace the production of red blood cells, diluting haemoglobin in the blood – a change sometimes called physiological anaemia of pregnancy.

Iron deficiency occurs when:

• The diet does not provide enough iron
• Absorption of iron is reduced
• Iron needs are higher than usual, such as during pregnancy.

Even women who had adequate iron levels before pregnancy may find their iron stores depleted if intake does not increase to meet the heightened requirements. Alongside plasma dilution, iron is essential for producing haemoglobin, so insufficient iron intake can quickly lead to iron deficiency anaemia.²

Although iron deficiency is the most common cause during pregnancy, other forms of anaemia may also occur. For example, deficiencies in vitamin B12 or folate can result in different types of anaemia. These are less common but important to detect, as treatments differ.¹

By understanding these causes, healthcare providers can offer guidance on dietary adjustments, iron supplementation and regular monitoring to help maintain healthy blood levels throughout pregnancy.

How to treat anaemia in pregnancy

Anaemia in pregnancy should always be diagnosed and monitored by a healthcare professional. Self diagnosis is not advised, as symptoms such as fatigue, weakness or shortness of breath may overlap with normal pregnancy changes.²

Medical guidance first

If blood tests confirm anaemia, your midwife or GP will explain the type and likely cause. For iron deficiency anaemia, iron supplements are commonly recommended, but only under medical supervision. You should not start taking iron supplements during pregnancy unless advised to do so by your healthcare provider.

Taking iron without guidance is not recommended because too much iron can be harmful. Excess iron may lead to digestive discomfort, nausea or constipation, and very high doses could potentially affect the baby’s health. By following your healthcare provider’s advice, you can safely correct iron deficiency while ensuring both you and your baby receive the right support.

Nutrition and iron absorption

Iron rich foods include red meat, poultry, lentils, spinach, beans and fortified cereals. However, simply upping your iron intake might not be enough. You may also need to support how well your body absorbs the iron you consume.

Vitamin C enhances iron absorption, so including vitamin C rich foods or a supplement such as Nutraxin Vitamin C 1000 mg Tablet alongside iron-containing meals may help to support uptake.⁴ Consider adding some of these vitamin C sources to your meals:

• Oranges and other citrus fruits
• Strawberries
• Kiwi
• Bell peppers
• Broccoli.

On the other hand, substances like tea or coffee can inhibit iron absorption if consumed with meals. Your care team may suggest spacing these drinks away from iron-rich meals or supplements, or taking a break from them altogether over the course of your pregnancy.

Other nutrients and anaemia

In some cases, deficiencies of other nutrients such as vitamin B12 or folate may be involved. These conditions require specific diagnoses and tailored treatment, which your healthcare provider will discuss with you.

Severe anaemia and alternative treatments

If iron supplements are not well tolerated, or anaemia is severe, your healthcare team may recommend alternative approaches. These may include different formulations or supervised therapeutic interventions based on your individual health needs.

Medical and emotional support

Anaemia in pregnancy can feel alarming, but routine antenatal care and monitoring mean that it’s usually detected early. Maintaining open communication with your midwife or doctor can help to address concerns promptly and ensure that appropriate nutritional or medical support is in place.

Anaemia should never be self assessed during pregnancy. If you have symptoms such as extreme tiredness, dizziness or palpitations, speak to your healthcare team as soon as possible.

References

1. National Institute for Health and Care Excellence. (2021). Antenatal care for uncomplicated pregnancy.
   https://www.nice.org.uk/guidance/ng201
2. World Health Organization. (2023). Anaemia. https://www.who.int/health-topics/anaemia
3. British Dietetic Association. (n.d.). Iron requirements in pregnancy.
   https://www.bda.uk.com/resource/iron-requirements-in-pregnancy.html 
4. National Institutes of Health, Office of Dietary Supplements. (2023). Iron – Fact sheet for health professionals. https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/