IMMUNORho

Indications

Human Anti-D Immunoglobulin is used to prevent Rh disease (haemolytic disease of the fetus and newborn) in future pregnancies. It is given to Rh-negative women who are carrying or have delivered an Rh-positive baby, or after events that may let the baby's blood enter the mother's circulation, such as miscarriage, abortion, ectopic pregnancy, amniocentesis, bleeding in pregnancy or abdominal injury. It is also given routinely during pregnancy in many programmes, and after transfusion of Rh-positive blood to an Rh-negative person.

How It Works

Anti-D immunoglobulin is a preparation of antibodies collected from donor plasma. When given, these antibodies quickly attach to any Rh-positive (D-positive) red blood cells from the baby that have entered the mother's blood and remove them before her immune system notices them. This stops the mother from making her own permanent anti-D antibodies, which could cross the placenta and destroy the red blood cells of a future Rh-positive baby.

Dosage and Administration

Given by a doctor, midwife or nurse as an injection into a muscle (or, for some products, into a vein). The dose and timing depend on the situation (routine dose in pregnancy, after delivery or after a sensitising event) and on blood tests that measure how much fetal blood has entered the mother's circulation, so it is given as prescribed. After delivery or a sensitising event it should be given as soon as possible, ideally within 72 hours.

Interactions

Live vaccines such as measles, mumps and rubella (MMR) and varicella may work less well if given within about 3 months after anti-D; the doctor may check immunity later. If MMR is given just after delivery, anti-D can still be given, but antibody levels may be checked afterwards. Anti-D can interfere with some blood tests for a few weeks.

Contraindications

Do not give to anyone allergic to human immunoglobulins or any ingredient. It is not given to Rh-positive people for this purpose, or to Rh-negative women who already have anti-D antibodies from earlier sensitisation. Products for muscle injection should not be used in people with severe low platelets or bleeding disorders; a vein product may be used instead.

Side Effects

Common side effects include pain, tenderness or swelling at the injection site, mild fever, chills, headache, tiredness and nausea. Rarely, allergic reactions, including severe ones, can occur, especially in people with IgA deficiency. When given into a vein, breakdown of red blood cells can occur in some situations.

Get urgent medical help for difficulty breathing, wheezing, swelling of the face or throat, widespread rash, fainting, chest tightness, dark urine, yellowing of the skin or back pain after the injection.

Pregnancy and Lactation

Anti-D immunoglobulin is specifically intended for use during pregnancy and after delivery and is considered safe for mother and baby. It can be given while breastfeeding.

Precautions and Warnings

• Blood group and antibody screening are done before use.
• Because it is made from human plasma, there is a very small theoretical risk of passing on infections, although donor screening and manufacturing steps make this extremely unlikely.
• The patient is watched for at least 20 minutes after the injection for allergic reactions.
• Keep a record of the dose and date; you may need it in future pregnancies.

Overdose

There is no known harm from extra doses in Rh-negative women, apart from more injection-site discomfort. In Rh-positive people or when large doses are given into a vein, breakdown of red blood cells may occur and is treated in hospital.

Therapeutic Class

Immunoglobulin (Rho(D) immune globulin, human)

Storage

Store in a refrigerator at 2 to 8°C, do not freeze, and protect from light. Given by health professionals; keep out of the reach of children.