No, it makes no sense that the same blood group would have a negative effect on the pregnancy. The Rh factor is the problem when the baby (and baby's father) have a Rh+ blood and the mother has Rh- blood. When that happens the baby's blood could "poison" the mother and cause a severe reaction on the mother after delivery but that is easily fixed by a shot that your dr. gives you.
don't think so. the only problem i know of with blood groups and babies involves negative blood groups.