What should you know about RhD immunoglobulin injection?

It may be offered when you are RhD negative and pregnancy, birth, bleeding, abdominal injury, or a procedure could allow fetal blood cells into your bloodstream. The medicine supplies ready-made antibodies that clear RhD-positive cells before your immune system learns to recognise them. This is called preventing Rh sensitisation. It protects future pregnancies from problems caused by antibodies crossing the placenta and affecting a fetus's red blood cells.

The injection is different from a vaccine and does not change your blood type. Your maternity team decides whether it is appropriate after considering your blood group, pregnancy stage, and what has happened.

Tell the clinician your blood-group history, allergies, previous reactions to blood products, and any recent bleeding or procedure. Follow the timing advised by your maternity team because protection is linked to when a possible blood-mixing event occurred. You may notice soreness at the injection site, tiredness, headache, or a mild temperature. Keep the appointment details and report a reaction that is severe, spreading, or worsening.

Contact your maternity service promptly after vaginal bleeding, fluid loss, abdominal trauma, contractions, or an invasive procedure in pregnancy, even if you feel well. Seek urgent help for heavy bleeding, severe abdominal pain, fainting, trouble breathing, facial swelling, or reduced fetal movement when you have been advised to monitor it. These symptoms need assessment; do not wait to decide whether an injection is needed.

Ask whether your blood group makes RhD immunoglobulin relevant, which events require it, when it should be given, and which symptoms after the injection should prompt a call.