Just to correct a few points from the last poster:
We didn’t know it was RH until after she was born with growth problems and jaundice.
You know your baby's blood type immediately after birth, and are given anti-D immediately. (It's nothing to do with any issues like you mentioned)
However, the issue is with you (the mother) being RH negative, and your baby being RH positive. (Not the other way around, as you describe).
That's because it's the RH negative blood that makes the antibodies. The RH positive blood will not (which is why RH negative is the universal donor, and can be given to any blood type).
So if you are RH+ none of the rhesus disease issues are relevant.
Perhaps that poster meant to write that they are RH negative & the baby is positive, which would make sense.
Finally, it's subsequent pregnancies that are affected, not first pregnancies; due to the development of antibodies that affect the blood of the next baby in utero. As blood type is noted on your notes, you'll be carefully supervised during pregnancy to make sure there's no possibility of blood transfer in pregnancy (eg if you had a fall or a tip in a car).