Anaemia in pregnancy

Feeling tired during pregnancy is common, so it is not always obvious when tiredness might have another cause. Anaemia means the level of haemoglobin in your blood is lower than normal. Haemoglobin is found in red blood cells and carries oxygen around your body.

Mild anaemia is common during pregnancy, and iron deficiency is a frequent cause. Blood tests are part of routine antenatal care and can identify anaemia even if you have not noticed symptoms. If you are diagnosed, your maternity team can investigate the cause and recommend appropriate care.

What causes anaemia in pregnancy?

Pregnancy places additional demands on the body, including an increased need for the nutrients used to make healthy red blood cells.

Iron deficiency is the most common type of anaemia. The NHS explains that pregnancy is a common cause of iron deficiency anaemia. Your body needs iron to make haemoglobin, so if your iron stores become too low, your haemoglobin can fall.

Iron deficiency is not the only possible cause. Low levels of vitamin B12 or folate can also cause anaemia. Inherited blood conditions, including sickle cell disease and thalassaemia, can affect haemoglobin too.

Because different types of anaemia need different assessment and care, it is better to have blood tests than to assume low iron is the reason for your symptoms.

What are the symptoms of anaemia in pregnancy?

Anaemia can cause symptoms, but some people have few or no obvious signs.

The NHS lists common symptoms of iron deficiency anaemia including:

tiredness and lack of energy
shortness of breath
noticeable heartbeats or palpitations
paler skin than usual
headaches

RCOG also lists fainting among possible symptoms of anaemia. More severe anaemia can make someone feel very unwell and may cause dizziness, significant breathlessness or chest pain.

Many of these symptoms can have other causes, and pregnancy itself can change how you feel. Symptoms alone cannot confirm anaemia.

If you are unusually tired, breathless, dizzy or experiencing other symptoms that concern you, tell your midwife or GP rather than assuming they are simply part of pregnancy.

How is anaemia diagnosed during pregnancy?

Anaemia is diagnosed with a blood test.

A full blood count measures haemoglobin as well as other blood cells. RCOG states that haemoglobin is routinely checked at the first pregnancy appointment and again at around 28 weeks.

Your maternity team may arrange additional tests if your result is low or if there is a reason to investigate your iron stores or another possible cause.

Iron deficiency and anaemia are related but are not exactly the same thing. Your iron stores can become low before your haemoglobin falls enough for you to be anaemic. Healthcare professionals may use additional blood tests when they need to understand the cause of a low haemoglobin result.

Is anaemia common during pregnancy?

Some degree of anaemia is common in pregnancy.

Part of the reason is that pregnancy changes the volume and composition of your blood. At the same time, the body has increased nutritional demands.

That does not mean symptoms should automatically be dismissed as normal. Routine antenatal blood tests are there to identify anaemia and other blood-related changes that may need attention.

If a blood test shows that you are anaemic, your healthcare team can explain how low your haemoglobin is, what they think is causing it and whether you need treatment or further testing.

How is iron deficiency anaemia treated?

Treatment depends on the cause and severity of the anaemia.

For iron deficiency anaemia, iron tablets are commonly used to replace missing iron. RCOG notes that iron tablets or syrup may be offered when anaemia is caused by iron deficiency or blood loss.

Some people experience side effects from oral iron, such as constipation, diarrhoea, stomach discomfort, heartburn, nausea or darker stools. If side effects are difficult to manage, speak to your midwife, GP or maternity team rather than stopping prescribed treatment without advice.

In some circumstances, an iron infusion may be considered, particularly if oral iron cannot be tolerated or has not worked adequately. More severe anaemia may require different care, and blood transfusion can sometimes be needed, particularly in situations involving significant blood loss.

Your healthcare team should recommend treatment based on your blood results and individual circumstances. Do not begin high-dose iron or change prescribed treatment without professional advice.

Do you need to take iron supplements throughout pregnancy?

Routine iron supplementation is not recommended for everyone.

RCOG states that most pregnant people do not need extra iron supplements routinely. Blood is checked during pregnancy, and iron may be recommended if you are found to be anaemic or considered at increased risk.

This matters because more is not automatically better. Iron supplements can cause side effects, and anaemia can have causes other than iron deficiency.

If you are considering an iron supplement because you feel tired, speak to your midwife, GP or pharmacist first. They can advise whether blood testing or supplementation is appropriate.

What foods contain iron?

A varied diet can provide iron, although diet alone may not be enough to treat diagnosed iron deficiency anaemia.

The NHS lists iron-containing foods including:

dark green leafy vegetables
pulses such as beans, peas and lentils
iron-fortified cereals and bread
meat
dried fruits such as apricots, prunes and raisins

RCOG also lists eggs, vegetables and cereals among sources of iron.

If you eat a vegetarian or vegan diet, have food allergies, experience significant nausea or food aversions, or find it difficult to meet your nutritional needs for any reason, tell your midwife. They can help you access appropriate dietary advice.

Do not rely on food changes instead of prescribed treatment if you have been diagnosed with anaemia.

Why does anaemia matter during pregnancy and birth?

Haemoglobin carries oxygen around the body, so significantly reduced levels can affect how you feel and how well your body copes with additional demands.

RCOG explains that being very anaemic close to birth can make the effects of blood loss during birth more significant. Severe anaemia can also cause symptoms such as dizziness, breathlessness and chest pain.

This is one reason antenatal teams check haemoglobin during pregnancy and treat anaemia when necessary.

A diagnosis does not mean that complications will happen. The significance of anaemia varies according to its cause, severity, your symptoms and other aspects of your health. Your maternity team can explain what your individual results mean.

What happens after treatment starts?

Your healthcare team may arrange repeat blood tests to see whether your haemoglobin and iron levels are improving.

How quickly your blood results change depends on the cause of the anaemia and the treatment being used. Keep attending the follow-up appointments and blood tests recommended by your maternity team.

If treatment does not appear to be working, or you cannot tolerate it, contact the healthcare professional looking after you. Further assessment or another treatment option may be appropriate.

When to get professional advice

Speak to your midwife or GP if you think you may have anaemia or develop persistent tiredness, shortness of breath, palpitations, headaches, dizziness or unusual paleness. These symptoms can have several causes, so medical assessment is more useful than trying to diagnose anaemia yourself.

If you have already been diagnosed, contact your maternity team if your symptoms are worsening, you are struggling with prescribed treatment or you have questions about supplements or your blood test results.

Seek urgent medical advice if you develop severe breathlessness, chest pain, fainting or feel seriously unwell. Contact your maternity unit if you have its number, or NHS 111 if you cannot reach your maternity service or are unsure where to seek help.

Call 999 for a life-threatening emergency.

You should also contact your maternity team promptly for any urgent concern about your pregnancy or your baby’s wellbeing, regardless of whether you think it is connected to anaemia.