Anaemia in pregnancy
Date issued: July 2019
For review: July 2021
Ref: C-384/LR/Maternity/Anaemia in pregnancy
PDF: Anaemia in pregnancy [pdf] 169KB
What is anaemia?
Anaemia is when the level of haemoglobin in your blood is lower than normal. Haemoglobin carries oxygen from your lungs to cells around your body. If your haemoglobin count is low then your body does not work as well as it should. Iron is one of the minerals that your body needs to produce haemoglobin.
A healthy diet is generally enough for most people to avoid anaemia. The main sources of iron in your diet are red meats, poultry, fish, beans, lentils, eggs and dark leafy vegetables.
How can anaemia affect me?
Anaemia can cause tiredness, breathlessness, fainting, headaches and your heart to beat faster.
Mild anaemia is common during pregnancy and your haemoglobin level will be routinely checked at your first pregnancy appointment and at around 28 weeks. Pregnant women may not get enough iron to keep pace with their increasing blood supply and that of their growing baby. Many women need more iron when they are breast feeding and some babies need extra iron too.
Why do I need to have treatment for anaemia?
It is important to treat anaemia in pregnancy for many reasons. There is always a risk of bleeding when you have a baby and if you are already anaemic this can increase the risks for you and make it more likely that you will need a blood transfusion. Anaemia has also been linked to depression and making it more difficult to fight infection. Babies can be anaemic too and there is a possibly increased risk of prematurity and small babies.
Some people are more at risk of being anaemic and may be tested more frequently or advised to take iron supplements.
These people include, vegetarians, teenagers, women expecting twins, women who previously had very heavy periods and women who had a baby less than a year ago or have had many children. Some women are not at an increased risk of anaemia but are at a higher risk of bleeding, these women may also be advised to take supplements during pregnancy.
Iron replacement
If you have anaemia because of blood loss or lack of iron, you may be offered iron tablets to restore your haemoglobin level instead of a blood transfusion. It will take longer for you to feel completely well but you avoid the minimal risks associated with blood transfusion.
For the tablets to work well, it is advisable to have a source of vitamin C (such as a small glass of fresh orange juice) at the same time. The tablets are best taken on an empty stomach. Tea and coffee reduces iron absorption from your diet and so should be avoided at mealtimes.
You may get some side effects with the tablets such as an upset stomach or constipation. You may find that your stools become dark. If the side effects are bothering you, try taking two tablets a day (if you have been given three per day) or try taking them with food. There are other preparations that may suit you if these measures do not work.
You may be advised to take folic acid, in addition to taking iron, to raise your haemoglobin level. Once your level of haemoglobin is normal you will need to continue taking supplements for at least a further 3 months (if you are pregnant) or 6 weeks (if you have had the baby) to build up your iron stores.
Iron infusion
If you are unable to take iron tablets or your anaemia doesn’t respond to iron tablets, you may be offered an iron infusion. Occasionally you will be offered an infusion if you are approaching your due date as this treatment works more quickly than giving you tablets.
The iron is given through a drip in your arm. This can be given after the first 3 months of pregnancy. It is safe for you and your baby.
There is a low risk with all iron treatments given directly into your arm but there can be exceptions.
Side effects
These are often, mild and include headaches, nausea, soreness or redness around the injection site and elevated blood pressure. These side effects do not tend to last very long and usually don’t require any other treatment.
Rare reactions
This is known as an Anaphylactoid reaction, also known as “severe hypersensitivity reaction”. This happens to less than 5 people per 10,000 (0.045%). The symptoms are swelling of the face, mouth and tongue and possibly causing difficulty in breathing.
What happens when you have the iron Infusion?
After the drip is placed in your arm and the iron infusion if started it will take around 15 minutes to be given. You will be observed in the department for another 30 minutes after the infusion is complete.
Important things to be aware of
The iron medication is brown in colour and so it is very important that when you have the intravenous (IV) infusion of iron that you keep your arm still and not bend it as this may lead to leaking of the iron into the surrounding tissue. This may cause irritation of the skin and long lasting discolouration of the skin.
Please inform the staff immediately is you have pain at the site of the “drip”. You will be monitored for this and treatment provided if required. If after you go home you have any concerns then please contact triage.
Do I need more than one dose of iron infusion?
Some people need to return for a second dose. This will be discussed with you and depends on how anaemic you are.
You are advised to avoid taking oral iron supplements for 5 days after the final infusion and then to recommence taking iron as prescribed
You will need to have a blood test after 2-3 weeks to make sure that your anaemia has responded to the treatment.
