Rh is a type of protein found on the surface of a person's red blood cells. If a woman does not have the Rh factor it means she is Rh negative. If a woman wants or needs to know if she is Rh negative, a blood test will be able to determine that. Keep in mind once a woman is pregnant blood work is done at the first doctor appointment to determine her blood type, so the doctor will know whether the woman is Rh negative.
Antibodies and Rh Negative Blood
If a woman does not have the Rh factor (Rh negative) it means her body could possibly produce antibodies, which can cross the placenta and attack the fetus's blood. Antibodies can develop when the mother's blood and the fetus's blood mix. This is called sensitization. Sensitization can occur when there is a:
- Miscarriage
- Induced abortion
- Menstrual extraction
- Ectopic pregnancy
- Chorionic villus sampling
- Blood transfusion
When sensitization occurs and antibodies are produced, the antibodies can break down the fetus's red blood cells, which can produce anemia in the fetus. This is medically known as hemolytic disease or hemolytic anemia. It can cause serious illness, brain damage and in rare cases, death.
Preventing Antibodies
Around week 28 during the pregnancy an Rh immunoglobulin (RhIg) injection is given to help prevent sensitization in a woman who is Rh negative. This injection, commonly known as Rhogam, will also be given to the woman if she has any bleeding during the pregnancy. The rhogam shot will also be given if the woman has a miscarriage, ectopic pregnancy, induced abortion, after amniocentesis and after getting her fallopian tubes tied. If after delivery the baby is determined to have the Rh factor (Rh positive) the woman will need another Rhogam shot. If the baby is Rh negative, no shot is needed because antibodies may only be produced during the pregnancy if the baby is Rh positive and the mother is Rh negative.
When Antibodies Develop
If antibodies develop during the pregnancy, a rhogam shot will not help. The doctor will check to see if the fetus is developing the condition. Most commonly a blood transfusion will be performed after the baby is delivered full-term. In severe cases the baby may need a blood transfusion while in the womb and may need to be delivered early.
As long as a woman gets prenatal care and her doctor takes the necessary precautions, there is no need to worry about being Rh negative. Many Rh negative women have successful pregnancies. The Rh factor does not affect a person's general health and more than 85 percent of the United States' population is Rh positive.
Source: American Pregnancy Association, “Rh Factor” (accessed December 12, 2010)
Tamara Frank - My name is Tamara Frank and have been writing for Suite101 for two years. I have self-published a book titled "Lessons I Learned From ...
