I have type c antibodies. They were discovered during my 3rd pregnancy.
Basically it can be a problem and i'm afraid you probably can't avoid a hospital birth now.
Mine started off at quite a low level but once the level rose to over 4, I had to have my antenatal care transferred to a larger hospital.
I had to have weekly blood tests and fortnightly scans to check hydrops which is water under the skin. This is a sign of anemia iirc.
Thankfully all throughout the pregnancy my baby was fine and didn't need any treatment. In severe cases sometimes the baby needs a blood transfusion whilst still in the womb.
Ds was born at 37 weeks and was very jaundiced but thankfully only needed treatment on a billybed so stayed with me. He was jaundiced for about 2mths and then once that cleared up he became anemiac and narrowly escaped a blood transfusion.
Since then though he has been fine and is a perfectly healthy nearly 4 yr old.
I was told that your level of antibodies can be really high and baby not be affected or that it can be really low and baby can be really poorly, apparently it depends on the baby.
I think that by the end of the pregnancy my level was 5. something and with any further pregnancies (not advised) the level starts off at where it finnished at end of last pregnancy.
It is very hard to find out info on the net that doesn't scare you half to death tbh, but all I can say is that my experiance of it was that you are monitered very closely if needed and would be treated very quickly if needed and that it's not such a BAD thing as some doctors make it sound.