Anti-D Injections in Pregnancy: A Complete Guide
Everything UK parents need to know about Anti-D injections in pregnancy: when they are given, why they matter, and what to expect.
Table of Contents
What Anti-D Is and Why It Is Offered
Anti-D immunoglobulin is a purified blood product given to Rhesus negative (RhD negative) pregnant people to prevent their immune system from making antibodies against RhD positive blood. Without Anti-D, sensitisation can occur when baby blood cells enter your circulation, usually during birth but also after bleeding, miscarriage, or trauma. Once antibodies form they cannot be removed, and they can attack the blood cells of future RhD positive babies. Anti-D effectively mops up any baby blood cells before your immune system notices them.
When You Will Receive Anti-D
In the UK, routine Anti-D is offered as a single dose at 28 weeks of pregnancy. A second dose is given within 72 hours of birth if your baby cord blood test confirms they are RhD positive. Additional doses are recommended after any sensitising event: bleeding in pregnancy, abdominal trauma, ectopic pregnancy, miscarriage after 12 weeks, or invasive procedures such as amniocentesis or CVS. The injection is usually given into the upper arm or thigh muscle and may cause mild local soreness for a day or two.
Frequently Asked Questions
Is Anti-D made from blood donations?
Yes, Anti-D immunoglobulin is made from human plasma donated by people with high levels of Anti-D antibodies. All donations in the UK are screened and treated to reduce the risk of infection.
Does the Anti-D injection hurt?
Most people describe it as similar to any other intramuscular injection. You may feel a brief sting and some soreness or redness at the injection site for 24 to 48 hours. Serious side effects are very rare.
Can Anti-D fail to prevent sensitisation?
Anti-D is highly effective but not 100 percent. A small number of people still develop antibodies despite treatment, which is why your blood is retested for antibodies at 28 weeks and after birth.
This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your midwife, GP, or obstetrician about your individual results and care plan.
Further reading:
Related articles: Early Pregnancy Blood Tests | hCG Levels Explained | Anaemia in Pregnancy