D-Gam injection contains a medicine called human anti-D immunoglobulin. It is given to pregnant women who have a blood type known as rhesus negative.
People whose blood type is rhesus positive (RhD positive) have a substance called D antigen on the surface of their red blood cells. People whose blood type is rhesus negative (RhD negative) are missing this antigen. Whether a person is rhesus positive or rhesus negative is determined by their genes.
Having a rhesus negative blood type is not usually a problem. However, if a rhesus negative woman is pregnant and her baby is rhesus positive it may cause problems.
If blood cells from a rhesus positive baby get into the rhesus negative mother's bloodstream, her blood will react as if the baby's blood is a foreign substance and will produce antibodies against it. This is not usually a problem in a first pregnancy with a rhesus positive baby. However, the antibodies that the mother produces stay in her blood, and if she has another pregnancy with a baby who is also rhesus positive, her antibodies can cross the placenta and attack the blood cells of the unborn baby. This can cause 'haemolytic disease of the newborn'.
Haemolytic disease of the newborn can be very mild, but in a small number of babies it can be more serious and cause the baby to be stillborn, severely disabled or to die after birth as a result of anaemia and jaundice.
The most common time for a baby's blood cells to get into the mother's blood, causing her to produce antibodies, is at the time of birth. However, this can also occur at other times, for example during a miscarriage or abortion, or as the result of having an amniocentesis, chorionic villus sampling, vaginal bleeding, or turning the babys head down (external cephalic version). These events are called 'potentially sensitising events'.
To prevent rhesus negative women producing antibodies against their baby's blood during pregnancy they can be given an injection with anti-D immunoglobulin. This treatment is called anti-D prophylaxis. It prevents the mother's immune reaction that could cause haemolytic disease of the newborn in her next child.
Anti-D prophylaxis is offered routinely to pregnant women who are rhesus negative, unless they already have anti-D antibodies in their blood. (This is tested by a blood test at the start of the pregnancy.) D-Gam injection is given as two doses at weeks 28 and 34 of the pregnancy. The treatment is offered regardless of whether a sensitisation event has occurred, in order to be absolutely certain that the mother does not develop antibodies against the baby.
After the birth, a blood sample will be taken to test the baby's blood group. If the baby is rhesus positive, the mother will be given a further injection of anti-D immunoglobulin. (This is called postnatal anti-D prophylaxis.) Another dose of anti-D immunoglobulin will also be given after any sensitising event (see above) that occurs during the pregnancy.
Anti-D prophylaxis may not be necessary for rhesus negative mothers if there is certainty that she will not have another child following the pregnancy, for example if she is to be sterilised after the birth. It will also not be necessary if the father's blood type is also rhesus negative, as genetically this means the baby cannot be rhesus positive.
Anti-D immunoglobulin may also be used if a rhesus negative individual is given a blood transfusion of rhesus positive blood. This is to prevent the individual forming antibodies against the transfused blood.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
If you need to be given this medicine within two to four weeks of having a live vaccine, such as yellow fever, BCG or oral polio, the anti-D immunoglobulin may interfere with the immune response to these vaccines. This could make them less effective. Discuss this with your doctor.
If live vaccines are needed after having an anti-D injection, they should be postponed until three months after the last injection of this medicine has been given. However, the MMR vaccine can be given at the same time as the postnatal dose of this medicine if necessary.