Does Rh Incompatibility Affect First Pregnancy?

Rh incompatibility usually doesn't cause problems during a first pregnancy. The baby often is born before many of the antibodies develop. However, once you've formed Rh antibodies, they remain in your body. Thus, the condition is more likely to cause problems in second or later pregnancies (if the baby is Rh-positive).

Why is Rh incompatibility usually not a problem during a first pregnancy?

Rh incompatibility usually isn't a problem if it's the mother's first pregnancy. That's because the baby's blood does not normally enter the mother's circulatory system during the pregnancy.

Does Rh negative affect first pregnancy?

If you're Rh negative and your baby is Rh positive, your body might produce proteins called Rh antibodies after exposure to the baby's red blood cells. The antibodies produced aren't a problem during the first pregnancy. The concern is with your next pregnancy.