What if the mother has o negative blood and the father is o positive can they have a healthy baby ?

You betcha!: Remember the best way to have a healthy baby is good prenatal care. Choosing a good OB is essential in monitoring the progress of the new baby. The blood types mentioned here are not rare. With good care before the delivery and a good pediatrician monitoring the baby after birth...Look forward to many happy years ahead.

Yes: The blood types are compatible. The obstetrician will also make sure there are no problems with future children by treating rhesus incompatibility. That is to say if your child is o+ and you get exposed to that blood during delivery, you might develop antibodies which could hurt your second child.