i had this, as I am a negative blood type.
it basically means, if your baby is a positive blood type, it can affect your baby if you are a negative blood type but if your partner is a negative bloodtype your baby should be negative also.
You should be given an Anti-D injection, to help prevent your antibodies attacking your baby.
I think the only thing it can do to a mum is if the blood from baby goes into mum, mum can have problems in her next pregnancy.
this is what i have taken from my baby book:
"when the cells from the baby's blood mix with the cells from mum, for example during delivery, the mums blood becomes sensitized. when the Rh factor from baby's blood enters mums blood stream, it acts as an antigen and stimulates anti-rhesus-positive antibodies. These will attack and destroy the blood cells of her next Rhesus-positive (incompatable) baby. this can cause haemolytic disease of the newborn and infants infected with blood conditions ranging from mild jaundice to serious possibly fatal anaemia. Most fetuses who develop the disease can often be saved by intauterine blood transfusion"
it says all women who are rhesus negative should be offered an Anti-D injection at 28 and 34 weeks of pregnancy and after delivery of a RH-positive baby.
So basically, you should have been given that Anti-D injection, and one within 48hours after birth (if your partner is a positive blood type) which will help prevent any further complications happening to subsequent pregnancies.
I had the injections at 28 and 34 weeks, and was due to have the injection after birth, but because my partner is the same blood type as me (negative) it didnt matter as it made our DD a negative bloodtype.
So maybe make the father have a bloodtest to see what his bloodtype is?
I so hope this made sense to you,(its late lol) and that its correct, maybe others can confirm/correct this??
good luck, not long till you meet your lil one!! gasp)