Intravenous iron infusion in pregnancy
You have been referred this page because you are anaemic. This means your blood has a lower level of healthy red blood cells than normal. This is often caused by low iron levels. Your doctor has advised that you have an iron infusion through a drip into a vein (intravenous iron), instead of taking iron tablets. The solution for the iron infusion may be ferric derisomaltose (Monofer®) or ferric carboxymaltose (Ferinject®).
Reasons for giving intravenous iron
- You are anaemic, and iron tablets have not worked, or they have made you feel unwell.
- You are anaemic following the birth of your baby.
- You have requested not to have a blood transfusion. Intravenous iron is not a blood product and does not have the risks of blood transfusions. Intravenous iron can sometimes be used instead of a blood transfusion. This may not be possible if you need blood urgently. Blood transfusions are safe, but there is a small risk of infection.
Suitability for intravenous iron
You should not have intravenous iron if you:
- have anaemia caused by deficiencies other than iron, such as B12 that has not yet been treated.
- have ever been told by a doctor that you have ‘iron overload’.
- have had an allergic reaction to iron given to you through a drip.
- have had a serious problem with your liver.
- currently have an acute or chronic infection.
Safety of intravenous iron
Intravenous iron is not usually given in the first 3 months of pregnancy. It can be given safely after this, including after you have given birth. Only a very small amount of intravenous iron passes into breast milk, so you can safely breastfeed.
Allergic reactions are uncommon. This means they happen in less than 1 in every 100 cases.
A serious allergic reaction, called anaphylaxis, is rare. This means it happens in less than 1 in every 1,000 cases.
You will be monitored closely during and after the treatment. If you have a reaction, staff will manage it safely.
How is intravenous iron given?
Intravenous iron is usually given when you are in the Antenatal clinic or on the Maternity Ward. Before starting the treatment, the midwife will check your pulse, blood pressure and temperature. If you are pregnant, your baby’s heartbeat will be checked.
A cannula, which is a small plastic tube, will be put into a vein in your arm. The intravenous iron infusion will be given through the cannula. This usually takes 15 to 35 minutes, depending on the dose you need.
After the infusion, the midwife will check your pulse, blood pressure and temperature again. If you are pregnant, your baby’s heartbeat will also be checked.
After the infusion has finished, you will need to stay for another 30 minutes. Your pulse, blood pressure and temperature will be checked again. If everything is stable, you will be able to go home. The treatment should not affect your ability to drive.
Side effects of intravenous iron
As with all medicines, intravenous iron can cause side effects.
Common side effects include:
- rash
- feeling sick (nausea)
- pain, bruising, irritation or swelling where the cannula for the drip was placed.
Less common side effects include:
- vomiting, tummy pain, diarrhoea or constipation
- metallic taste in your mouth
- flushing, fast heart rate, low or high blood pressure
- muscle and joint pains, backache and muscle cramps
- tiredness, chills, swelling, pins and needles
- headache, blurred vision and dizziness
- a high temperature, itching and a rash
- chest pain
There is a small risk that the iron infusion may stain your skin. This can look like brown discolouration. It may happen near the cannula site or further up your arm. Skin staining can be long lasting or permanent. It can happen if iron leaks around the cannula site or from the vein.
Please tell the midwife if you feel any pain or discomfort during the infusion. If this happens after you have gone home, please contact the unit where you had your iron infusion, your GP or the Emergency Department for advice.
What happens after the intravenous iron treatment?
Some women feel a little tired and their urine will be a darker colour the next day.
Most women notice that the symptoms of low iron levels, such as tiredness, shortness of breath and dizziness, start to improve within the following 2 weeks, but the infusion will take up to 4 weeks to have its full effect.
Do not take iron tablets for at least 2 weeks after your iron infusion, unless your doctor or midwife tells you to.
We recommend that you have a blood test 4 weeks after your infusion. This is to check your haemoglobin level, which shows the amount of red blood cells in your blood.
Contact information
If you have any questions after reading this page, please speak to the midwife before your infusion or contact us using the contact details below.
Antenatal Clinic
Tel: 0300 422 6104 or 0300 422 6103
Monday to Friday, 08:30 am to 4:30 pm
Maternity Advice Line
Tel: 0300 422 5541
Available 24 hours