Pregnancy

Rh Factor and Pregnancy

Rh factor is an antigen present in the red blood cells of about 85% of people, designated in Rh-positive or Rh-negative for those individuals lacking of this factor. Each individual has blood classified in 4 major type, A, B, AB or O that should be determined by tests performed with your blood is order to determine your blood type and factor screening as part of your pre-natal care.

These tests are aimed to find the blood type of your baby in case a problem or complication arises later, by either Rh compatibility or a particular condition. If the mother has blood where the Rh is -negative and the father is Rh positive, the baby can inherit the Rh factor from the father, leading to problems due to incompatibility with the mother's blood.

A mother who has blood that is Rh is -negative may develop antibodies to a baby with Rh positive and vice verse. If your baby's blood mixes with your blood, even in a minimal amount, your body may respond as if it were allergic to the baby, and blood mix between mother and baby occurs often. When you body makes antibodies to the Rh antigens in the baby's blood, they cross the placenta and attack your baby's blood.

Antibodies created by your body break down your baby's red blood cells producing anemia leading to severe illness of your baby, brain damage, or even the death as a fetus or premature death as newborn.

The procedure when your blood and your baby's blood mix is called sensitization. This may occur at any time, causing no harm if mother and baby have the same Rh factor, but leading to severe problems when an Rh-negative woman has had a miscarriage, an ectopic pregnancy, a blood transfusion, chorionic villus sampling or she has had an induced abortion or menstrual extraction.

All problems caused by Rh factor incompatibility can be prevented by early blood test that provides you with your blood type and your Rh factor. The doctor may ask for antibody screening, which is another blood test able to show if an Rh-negative woman has developed antibodies to Rh-positive blood during her pregnancy.

If the incompatibility is present, your doctor can apply and injection or Rh immunoglobulin (RhIg), which is a blood product capable of prevent sensitization of an Rh-negative mother, hence the baby's red blood cells will not be attacked. RhIg injections are often used during pregnancy and after delivery.

If an Rh-negative woman suffers a miscarriage, an ectopic pregnancy, or has an induced abortion, she will probably receive Rh immunoglobulin treatment after experience any of those problems, in order to prevent the developing of antibodies that would attack an Rh-positive baby in future pregnancies.