An injection that protects future pregnancies in rhesus-negative mothers
Anti-D immunoglobulin
An injection given to rhesus-negative mothers to prevent their immune system reacting to a rhesus-positive baby's blood and protect future pregnancies.
What is Anti-D immunoglobulin?
Anti-D immunoglobulin is a preventive injection given to mothers who are rhesus-negative, to stop their immune system reacting to a rhesus-positive baby's blood. Without it, a mother's body can make antibodies that could harm a rhesus-positive baby in a future pregnancy, a problem called haemolytic disease of the newborn. It is a blood product made from human plasma, given by injection, and is generally well tolerated. It is preventive, not a treatment for an illness, and is given at set times in pregnancy and after birth or other events that can mix the bloods.
Education and reference only. This is a plain-language guide to Anti-D immunoglobulin — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Anti-D immunoglobulin is a preventive medicine given to mothers who have rhesus-negative blood. If such a mother carries a baby with rhesus-positive blood, some of the baby's blood can mix with hers, and her immune system may start making antibodies against it. These antibodies usually cause no trouble in that pregnancy but could attack the blood of a rhesus-positive baby in a future pregnancy, causing haemolytic disease of the newborn. Anti-D immunoglobulin prevents this from happening. It is a blood product derived from human plasma, given as an injection, under maternity care.
How it works
When a rhesus-negative mother is exposed to rhesus-positive blood from her baby, her immune system can recognise it as foreign and start making lasting antibodies against it. Anti-D immunoglobulin works by quickly mopping up any of the baby's rhesus-positive blood cells before the mother's own immune system has a chance to react and learn to make those antibodies. This stops her becoming sensitised, so future rhesus-positive babies are protected. Because it works by preventing sensitisation, it is given at the right times rather than to treat an illness that has already developed.
Company & origin
Originated / developed by: Specialist manufacturers.
A blood product given by injection in the UK to rhesus-negative mothers to prevent their immune system reacting to a rhesus-positive baby's blood.
Practical use
How to take Anti-D immunoglobulin
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by injection by your maternity team at the recommended times during and after pregnancy.
- Tell your team promptly about any bleeding in pregnancy, a fall to the bump, or a miscarriage, as a dose may be needed.
- Understand it is preventive: it protects future pregnancies rather than treating an illness now.
- Keep your maternity appointments so doses are given at the right times.
- Tell your team if you have had a previous reaction to a blood product or immunoglobulin.
Weighing it up
Advantages & disadvantages of Anti-D immunoglobulin
Advantages
- Prevents rhesus-negative mothers becoming sensitised, protecting future pregnancies.
- Helps prevent haemolytic disease of the newborn, a serious condition in babies.
- Generally well tolerated, with usually only mild injection-site reactions.
Disadvantages
- It is a blood product made from human plasma, so it carries the small theoretical risks of such products.
- It is preventive and must be given at the right times to work.
- It is given by injection, which some people find uncomfortable.
Practical use
Good to know
The key point is that anti-D immunoglobulin is preventive: it does not treat an illness in the mother or baby now, but stops the mother's immune system being sensitised so that future pregnancies are protected. It is offered to rhesus-negative mothers at routine points in pregnancy, after the birth if the baby is rhesus-positive, and after any event that can let the bloods mix, such as bleeding in pregnancy, a miscarriage or certain procedures. Because it is a blood product made from human plasma, it carries the theoretical risks that come with such products, although these are very small thanks to careful screening; it is generally well tolerated. The most common reactions are mild, such as soreness where the injection is given. Maternity teams keep a record of the mother's rhesus status and when doses are due.
Who should not take it / use with caution
- People who have had a serious allergic reaction to anti-D immunoglobulin or similar products should not receive it.
- It is used with care in people with certain antibody deficiencies, under specialist advice.
- It is not needed for mothers who are rhesus-positive or who are already sensitised, so rhesus status is checked first.
Monitoring
- Checking the mother's rhesus status and antibody levels through pregnancy.
- Recording when doses are given and when the next is due.
- Watching for any allergic-type reaction after the injection.
Side effects
- Soreness, redness or swelling where the injection is given.
- Occasionally mild fever, headache or feeling generally off.
- Rarely, allergic-type reactions, which should be reported straight away.
Key interactions
- It may affect how well some live vaccines work, so tell your team about recent or planned vaccinations.
- There are few other routine medicine interactions, but tell your team about all your medicines.
- Your team coordinates its timing with blood tests and any other treatments in pregnancy.
Available as: A solution for injection, given by the maternity team.
Answers
Anti-D immunoglobulin: frequently asked questions
What is anti-D immunoglobulin used for?
It is given to rhesus-negative mothers to prevent their immune system reacting to a rhesus-positive baby's blood, protecting future pregnancies.
Is it a treatment or a prevention?
It is preventive: it stops the mother becoming sensitised rather than treating an illness that has already developed.
Why do I need it after bleeding or a miscarriage?
Any event that can mix the baby's and mother's blood can trigger sensitisation, so a dose may be given to prevent it.
Is it safe, as it comes from blood?
It is a blood product made from screened human plasma, so it carries only very small theoretical risks and is generally well tolerated.
Do all mothers need it?
No. It is given to rhesus-negative mothers; those who are rhesus-positive or already sensitised do not need it, so rhesus status is checked first.
The wider class
About Immunoglobulin (rhesus prevention, blood product)
Anti-D immunoglobulin belongs to the immunoglobulin (rhesus prevention, blood product) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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