How does anti-d injection work?

If you are RhD negative and your baby may be RhD positive, fetal blood cells can sometimes enter your bloodstream during pregnancy, bleeding, abdominal injury, procedures or birth. Anti-D immunoglobulin binds to those cells and helps remove them, reducing the chance that your immune system becomes sensitised.

Sensitisation can matter in a later pregnancy because your antibodies may cross the placenta and affect an RhD-positive baby. Anti-D does not change your blood type and does not treat antibodies that your immune system has already made.

Your maternity team checks your blood group and may discuss when anti-D is advised, including after a possible mixing event. Tell them promptly about bleeding, a fall or blow to the abdomen, pregnancy loss, or an invasive procedure so they can assess whether treatment is needed and when.

The medicine is given by injection, usually into a muscle. Bring your blood-group information and ask what follow-up testing is planned. Your clinician can explain the product used and whether Rhesus Incompatibility applies to your pregnancy.

Seek urgent maternity advice for heavy bleeding, severe abdominal pain, fainting, shoulder-tip pain, fluid leaking, or reduced fetal movements after you have established a pattern. Do not delay contacting the team while deciding whether anti-D might be needed.

After an injection, seek help for trouble breathing, facial swelling, widespread hives or feeling faint. Mild soreness at the injection site can occur, but your clinician should assess symptoms that worry you.

Ask whether you are RhD negative, when anti-D is recommended in your situation, what to do after bleeding or injury, and whether a blood test is needed. You can also ask about expected injection effects and the Anti-D Injection plan for a future pregnancy.