You will be tested early during pregnancy to determine your blood type and your Rh (Rhesus) status. This is a protein which most people have on the surface of their red blood cells. An Rh-positive factor is never a cause of concern, but an Rh-negative factor indicates precautions during pregnancy and chances of Rh incompatibility with your baby. However you could make sure of it only once the baby is born and keep your fingers crossed till then.
If there is an Rh-incompatibility between your blood and that of the baby in the womb it may not be very significant in case of first pregnancies. However a leak of your baby’s blood into yours during pregnancy, labor and childbirth, would cause a release of antibodies from your immune system to attack the Rh-positive blood of your baby.
There could be leakage of blood even when you have an abortion, an ectopic pregnancy, a molar pregnancy, a miscarriage, a stillbirth, an external cephalic version (ECV), an abdominal injury during pregnancy, an invasive procedure, such as an amniocentesis or chronic villus sampling (CVS), or a bleeding from the vagina.
This intermingling will destroy your baby’s red blood cells and causing anemia, besides severe problems like new born jaundice, brain damage, miscarriage and stillborn. A shot of Rh immune globulin should therefore be taken whenever you suspect a chance of your blood being exposed to the baby’s blood.
You may have had Rh-negative blood even if you have suffered previous miscarriages, abortion or etopic pregnancy. If you have already not been desensitized by a shot of Rh immune globulin a test during a subsequent pregnancy may reveal it. The presence of antibodies spells danger to an Rh positive blood child. However the absence of antibodies in an Rh-negative mother provides her a chance to take the shot and protect the child.
Once you’re sensitized, you will have antibodies forever, produce more with each pregnancy. Your practitioner can help monitor your antibody levels and check on the condition of your baby’s red blood cells using Doppler ultrasound or amniocentesis.
Your baby can be given exchange transfusion to replace his diseased Rh-positive red blood cells with healthy Rh-negative cells, to stabilize the red blood cells levels and minimize further damage by antibodies in the bloodstream. Gradually these Rh-negative blood cells die off and making your baby’s red blood cells Rh-positive again.
It is interesting to note that Rh-positive fathers have a large possibility to have Rh-positive babies, similarly Rh-negative fathers have Rh-negative babies. However if the father’s Rh-status is not known an amniocentesis test can be done to examine the fetal cells from the amniotic fluid surrounding the baby in your uterus, if you have to test it before birth. However if you’re Rh-positive and your partner is Rh-negative, you might have an Rh-negative child.
