Why it’s important: If your Rh status turns out to be different from your baby’s there could be health problems for the baby and for your future pregnancies if your baby’s blood somehow mixes with yours (such as in a car accident or during amniocentesis). This is because your body may mount an immune response to what it perceives to be a “foreign invader” (your baby’s blood), and build up antibodies to prevent future “attacks”, which can affect future pregnancies.
Because we cannot test the baby’s blood type until birth, if your Rh factor type is negative (-), you will be automatically be given a shot of RhoGAM during pregnancy to prevent any potential complications. Giving this medication prevents the mother’s body from mounting an antibody response against an Rh positive baby in future pregnancies. The antibody screen detects other antibodies that may have the potential for causing blood disease in the fetus or newborn.