Anaemia in Pregnancy

The risks to mum and baby of being anaemic when pregnant

What is Anaemia?

Anaemia is the condition which occurs when there are not enough red blood cells in the blood. This leads to the person with anaemia having too little oxygen going to their brain, muscles and elsewhere.

Why do pregnant women become anaemic?

The main reason is that a woman’s body changes during pregnancy to look after the growing child.

Most commonly, Physiological Anaemia occurs when there is a decrease in the amount of haemoglobin and red blood cells being produced. In pregnant women, this is primarily due to an increased production of plasma* in the blood – during pregnancy plasma can increase by over 50%. The average woman will have about five litres of blood when not pregnant, but will have seven to eight litres of blood in her body as she gets near term. The body responds to this by increasing the production of red blood cells in the bone marrow. Within each red blood cell is a protein known as haemoglobin, its function is to carry oxygen absorbed by the lungs to organs and cells throughout the body. Oxygen is released by the red blood cells and is used by the body’s tissues to break down the necessary sugars and fats that are used as the body’s fuel. Once this fuel is used up it produces a waste product called carbon dioxide; which in turn binds to the red blood cells and is removed by the lungs.

Making the extra blood cells requires plenty of iron, vitamin B12 and folate to make all the extra haemoglobin needed. Unfortunately, iron is hard to absorb, which makes haemoglobin hard to make. So many women become anaemic during pregnancy unless they take iron supplements.

*Plasma is the liquid component of blood that helps transport red blood cells to vital organs. It is mostly made of water.

What else can cause pregnant women to become anaemic?

Pregnant women can become anaemic as a result of a number of conditions, these can include;

  • Dietary conditions such as low iron, vitamin B12 and folate intake
  • Malabsorption of nutrients such as in Coeliac Disease
  • Loss of blood resulting from haemorrhoids or stomach ulcers
  • Decreased bone marrow production resulting from infection or cancer
  • Inherited disorders such as thalassaemia and sickle cell anaemia

Symptoms of anaemia

 A person with mild anaemia will feel a little tired. A person with severe anaemia will feel like they are constantly out of breath, weak, dizzy, irritable and may find it hard to concentrate.

Many pregnant women develop mild anaemia.

Symptoms of anaemia can include;

  • Lethargy & tiredness
  • Weakness
  • Breathlessness
  • Dizziness
  • Heart palpitations
  • Difficulty concentrating
  • Irritability
  • Loss of appetite
  • Tinnitus (ringing in the ears)
  • In severe cases chest pain or headaches

How do I know if I have anaemia?

Your doctor will send you for a blood test at the commencement of your pregnancy and again in the second trimester. Any abnormality in the concentration of haemoglobin or the size, shape and number of red blood cells, will be picked up and may result in further tests being done. Further tests may include iron levels, Vitamin B12 and folate levels as well as genetic tests for inherited disorders such as thalassaemia.

The risks of being anaemic when pregnant? 

If a woman becomes anaemic while pregnant, it will make her even more tired than expected.

If the anaemia is severe, there could be a reduced amount of amniotic fluid around the baby. There is also an increased chance of miscarriage, early delivery or a low birth weight. Babies born from anaemic mothers may also be anaemic.

If a woman is anaemic throughout pregnancy and loses a lot of blood during the birth, she may need to have a blood transfusion around the time of the birth.

There are three good ways to avoid becoming anaemic while pregnant. They are starting pregnancy in good health, taking advised supplements and eating a healthy diet.

Pregnancy Resources