What Is Rh Factor?
Rh factor is a protein that we inherit which can be found on the surface of our red blood cells.  Blood is either Rh positive or Rh negative.  If your body produces the Rh factor, your blood is Rh positive.  If your blood does not have the Rh factor, you are Rh negative.  About 15% of the population has Rh negative blood.  The Rh factor is tested for early in pregnancy as part of routine blood testing.  It is noted on your prenatal record if you are Rh negative or positive.
 

How Does Being  Rh Negative Affect A Pregnancy? A woman’s health in pregnancy is not affected by having Rh negative blood.  Being Rh negative only becomes important if an Rh negative mother and a Rh positive father conceive a baby who inherits the father’s Rh positive blood.

When a Rh positive baby grows inside an Rh negative mother, some of the baby’s blood may leak into the mother’s.  This happens most often at the time of birth.  When the positive and the negative bloods mix, the mother’s body may react as if it had an allergy to the baby, making antibodies enter the baby’s bloodstream and cause the baby’s red blood cells to break down.  In a first pregnancy, there is very little danger of Rh disease because the baby is usually born before the mother develops antibodies. It is the next pregnancy that the danger of Rh disease is greater.  This is because the mother’s antibodies respond to the baby’s blood more strongly.

Can Rh Disease Be Prevented?

Rh disease can be prevented.  It is rarely seen today. If blood tests early in pregnancy show that a woman is Rh negative and that there is a need to prevent antibodies from forming, an injection of Rh Immune Globulin will be ordered for her by her doctor/midwife.  Rh Immune Globulin is a blood product and is usually given:
•  at 28 weeks of pregnancy;
•  and again within 72 hours after birth.

The other times when Rh Immune Globulin may be given is:
•  if bleeding occurs during pregnancy;
•  after a miscarriage, tubal pregnancy or 
    an abortion; and
•  with special tests such as amniocentesis.

 

How Does Rh Disease Affect a Baby? The breakdown of a baby's red blood cells can cause yellowing of the baby's skin and eyes (jaundice), low iron in the blood (anemia), heart failure or mental retardation.  In very severe cases, it can cause death.

How Does Rh Immune Globulin Work?

Rh Immune Globulin contains antibodies to the Rh factor.  The antibodies destroy any Rh positive blood from the baby that may have made its way into the mother’s blood.  Thanks to these “borrowed” antibodies,the mother’s body doesn’t make any of her own.  Protection from Rh immune globulin only last about 12 weeks, so treatment needs to be repeated with each pregnancy. Does Rh Immune Globulin Have Any Side Effects?

Reactions to Rh Immune Globulin are rare.  A small number of women may have some discomfort and a little swelling at the site of the injection and a slight increase in their temperature.  There is a remote chance of a severe allergic reaction in those with increased sensitivity to blood products.

Does Rh Immune Globulin Always Work? Rh Immune Globulin works very well in preventing Rh disease.  The blood test to see if the mother has produced any antibodies to Rh positive blood is repeated during pregnancy usually before  Rh Immune Globulin is given.  It is rare today to find a women who already has antibodies to Rh positive blood.  When this occurs, the woman’s doctor follows her pregnancy carefully.  Special tests can tell if Rh disease is developing.  If signs of Rh disease start to show, the baby may be delivered a little early to prevent the breakdown of the baby’s red blood cells.  Blood transfusions both before and after the baby’s birth may be used to treat the baby’s low blood (anemia) if it is severe.

Can Rh Immune Globulin Cause AIDS?

Blood that is donated for use in Rh Immune Globulin is checked for the AIDS virus and is treated with a substance that kills viruses and bacteria.  There have not been any cases of AIDS, hepatitis or any other infections linked to the use of Rh Immune Globulin.
 

Where Do I Go To Receive Rh Immune Globulin During Pregnancy? If you require Rh Immune Globulin, your doctor will send a referral to Medical Outpatients at the Peterborough Regional Health Centre.  You will be contacted for an appointment to have your blood drawn and receive your Rhogam injection. When you come for your apointment, remember to bring your health card.