Blood type B queens should be bred to blood type B toms to prevent NI in the kittens. In this situation all the kittens born will be blood type B and not at risk of NI.
If a blood type B queen is mated to a blood type A or AB tom then the kittens will need to be removed from the queen at birth and hand reared for the first 24-48 hours so that they do not suckle the colostrum and get the high dose of anti-A antibodies that can cause NI. After this time the kittens will be safe to return to the queen to continue suckling as normal.